John's Astronomy And Astrophotography Wiki - User contributions [en]

Dovetail Mounting Systems

2026-07-23T18:02:21Z

Jmh921: /* Disclaimer */

There are many ways of attaching a telescope to a mount. For some lower-end scopes, the scope is directly bolted to the mount head. For others, the scope's rings, if it uses rings, are directly bolted. For many high-end scopes and mounts, the mounting rings may also be directly bolted to the mount head. But for the majority of amateur telescopes in the mid and higher-end range, the mounting is done through a dovetail bar/plate and saddle method.

Over time, there have been several different specifications for these plates and saddles, with various manufacturers creating their own specifications for use with their equipment. However, over time, a few have become de-facto standards. The most popular such standards are known by the names of the companies that developed or at least popularized them: Vixen, Losmandy, and Synta.

Most dovetail bars are manufactured from extruded aluminum, though occasionally steel or other materials may be used. Aluminum typically provides sufficient strength while not adding significant weight. For lighter applications, some dovetails may be manufactured out of plastics, carbon fiber, or even wood, though these are much less common.

Note: ''The terms bar, plate, and rail are frequently used interchangeably to describe the portion which fits into the saddle, which will clamp down on the bar/plate/rail.''

Here is an example of a typical mounting saddle that would sit on top of the mount. This particular version is a dual-format saddle that can handle both Vixen and Losmandy-style dovetails.

[[File:DualSaddle.png|400px|Dual-mount saddle that can handle Vixen or Losmandy style dovetails.]]

==Vixen==

Using the Vixen-style system, the telescope payload (which may include the telescope itself, rings, cameras, finders, etc... ) are attached to a bar that is 43 mm (approximately 1.7 in) wide and 15 mm (0.6 in) high. The length varies depending on the size of the telescope to be attached. The sides of the bar are beveled at an angle of 15° from vertical, giving the bar a dovetail-shaped profile.

Here are some images of Vixen-style mounting bars:

[[File:Https---astrowiki.jmhastronomy.com-wikiimages-vr-220b-1s.png|200px|Top view of a Vixen-style dovetail bar.]]
[[File:Vixen-dovetail-red-bottom-view.png|200px|Bottom view of a Vixen-style dovetail bar.]]
[[File:Adm-vdup-11-1.png|200px|Another example of a Vixen-style bar.]]

Here is a mechanical drawing of the Vixen specification:

[[File:Vixen Profile.png|400px|Mechanical Drawing of a Vixen-style bar.]]

===Vixen Universal===

There is an older, alternative version of the Vixen dovetail that was originally designed for use with the Vixen Polaris German Equatorial Mount. The plate has some special notches cut for a more precise fit into the saddle. This plate is not found often, typically only on older telescopes. The notches are designed to fit the screws that clamp the bar onto the saddle. While the common Vixen and Losmandy style plates allow for the shifting of the payload forwards or backwards in the saddle along the length of the dovetail, the Vixen Universal plate does not allow this as the notches must be aligned to the clamping screws. This offers a more secure attachment, but, as previously stated, does not allow for shifting of the payload which is often useful for balancing the payload on the declination axis. In most cases, a modern standard Vixen saddle can accept the Vixen Universal plate, and vice-versa, but not always.

Here are some examples of the Vixen Universal dovetail bar:

[[File:OldStyleVixen.png|200px|Old-style Vixen dovetail bar.]]
[[File:VisenUniversalTop.png|200px|Vixen universal plate (old style), top view.]]
[[File:VixenUniversalBottom.png|200px|Vixen universal plate (old style), bottom view.]]

Here is a mechanical drawing of the Vixen Universal plate specification:

[[File:VixenUniversalSpec.png|400px|Vixen universal plate (old style), mechanical drawing.]]

==Losmandy==

A Losmandy-style dovetail plate, also referred to as the Losmandy D Series (to distinguish from the Losmandy V series, which are Vixen-style plates) serves the same function as a Vixen-style bar, but is wider and often used for heavier payloads. It also tends to provide more rigidity and stability. Aside from the overall width, one key difference between the Losmandy and Vixen style bars is that the dovetail portion of the Losmandy plate is typically fond underneath a wider portion for mounting the payload. The width of the dovetail, at its widest point, is approximately 3 inches wide, while the total width of the plate is roughly 4 inches wide. While the Vixen-style bar is 0.6 inches tall, the Losmandy is just short of 0.5 inches tall.

Due to the width and the fact that there is typically more surface area in contact with the saddle, they provide more stability and rigidity (as mentioned above). While you may often find telescopes with apertures of 8 inch (200 mm) or less frequently mounted on Vixen-style bars (though some users prefer the Losmandy plate), most larger telescopes will be found mounted on Losmandy-style plates.

These are some examples of the Losmandy D plate:

[[File:Losmandy-D-Top-View.png|200px|Losmandy D - top view]]
[[File:Losmandy-D-Top-View.png|200px|Losmandy D - top view]]
[[File:Losmandy-D-Bottom-View.png|200px|Losmandy D - bottom view]]
[[File:Losmandy-D-Actual.jpg|200px|Losmandy-made D plate (bottom view)]]

Here is a mechanical drawing of the Losmandy D specification:

[[File:Losmandy D Mechanical View.jpg|400px|Losmandy D mechanical drawing]]

==Celestron CGE==

Celestron, manufactured by the Synta Technology Corporation of Taiwan, sells most of its telescopes with a choice of mounting options. The first option they refer to as the CG-5 dovetail, named after the once-popular CG-5 mount. This is identical to the Vixen-style dovetail specification.

The other option they offer they refer to as the CGE dovetail, named after their CGE Pro mount, which used to be their premier German Equatorial Mount (GEM). Superficially it looks much like a Losmandy D plate, though it tends to have a curved portion while most Losmandy D plates rely on radius blocks for mounting larger scopes. However, while it looks similar, the specifications are slightly different and are not entirely compatible. A Losmandy-style dovetail saddle can usually handle a Celestron CGE plate, but a Celestron CGE saddle usually cannot handle a Losmandy-style plate.

Here are some images of Celestron CGE mounting plates:

[[File:CelestronCGEBottom.png|200px|Celestron CGE bottom view]]
[[File:CelestronCGETop.png|200px|Celestron CGE plate top view]]

Here is a mechanical drawing of the CGE specification:

[[File:CelestronSpecification.png|200px|A mechanical drawing of the Celestron CGE dovetail plate.]]

And here is a comparison of the Losmandy and Celestron dovetails:

[[File:Celestron Losmandy Comparison 1.jpg|600px|Comparison between CGE and Losmandy D profiles]]

==Synta==

The Synta dovetail mount, often referred to as the "Synta Shoe," is a smaller dovetail, similar in style to the Vixen, and primarily used for the mounting of accessory equipment, particularly finder scopes. Due to the fact that most items attached using this mounting method tend to be small, light accessories, many are manufactured from plastic, particularly through [https://en.wikipedia.org/wiki/Fused_filament_fabrication FDM] 3D printing methods using PLA, ABS, or PETG filaments.

The most common application, as mentioned, is for attaching finder scopes, but there are also synta mounts for things like [https://www.rigelsys.com/quikfinder.html Rigel Quickfinder] reflex sites, red-dot finders, counterweights, laser pointers, dew heater controllers, power distribution controllers, and computers like the [https://www.zwoastro.com/product/asiair-plus/ ZWO ASIAir].

Here are a few examples of Synta-style mounting hardware:

[[File:SyntaRedDot.png|200px|Red-dot finder on Synta mount.]]
[[File:SyntaDualMount.png|200px|Synta dual-mount adapter]]
[[File:SyntaRigelMount.png|200px|Synta mount for Rigel QuickFinder reflex site]]
[[File:SyntaComputerMount.png|200px|Synta mount for ASI Air or similar]]
[[File:SyntaFinderscope2.png|200px|Synta mount for finder scope, version 2]]
[[File:Synta finderscope mount.png|200px|Synta mount for finder scope]]
[[File:SyntaSaddle2.png|200px|Synta style saddle]]

Here is a mechanical drawing of the Synta specification:

[[File:SyntaMechanicalDrawing.png|200px|Synta saddle mechanical drawing]]

=Disclaimer=
Most or all of the images on this page are copied from third-party websites, mostly vendor sites. In particular I've used images taken from [https://agenaastro.com/ Agena Astro], [https://www.highpointscientific.com/ High Point Scientific], and [https://store-losmandy-com.3dcartstores.com/ Losmandy Astronomical Products]. If you are the owner or copyright holder of any of these images and would like me to remove them, please refer to my [[John's Astronomy And Astrophotography Wiki:General disclaimer|general disclaimer page]] with contact information].

Dovetail Mounting Systems

2026-07-23T18:00:36Z

Jmh921:

There are many ways of attaching a telescope to a mount. For some lower-end scopes, the scope is directly bolted to the mount head. For others, the scope's rings, if it uses rings, are directly bolted. For many high-end scopes and mounts, the mounting rings may also be directly bolted to the mount head. But for the majority of amateur telescopes in the mid and higher-end range, the mounting is done through a dovetail bar/plate and saddle method.

Over time, there have been several different specifications for these plates and saddles, with various manufacturers creating their own specifications for use with their equipment. However, over time, a few have become de-facto standards. The most popular such standards are known by the names of the companies that developed or at least popularized them: Vixen, Losmandy, and Synta.

Most dovetail bars are manufactured from extruded aluminum, though occasionally steel or other materials may be used. Aluminum typically provides sufficient strength while not adding significant weight. For lighter applications, some dovetails may be manufactured out of plastics, carbon fiber, or even wood, though these are much less common.

Note: ''The terms bar, plate, and rail are frequently used interchangeably to describe the portion which fits into the saddle, which will clamp down on the bar/plate/rail.''

Here is an example of a typical mounting saddle that would sit on top of the mount. This particular version is a dual-format saddle that can handle both Vixen and Losmandy-style dovetails.

[[File:DualSaddle.png|400px|Dual-mount saddle that can handle Vixen or Losmandy style dovetails.]]

==Vixen==

Using the Vixen-style system, the telescope payload (which may include the telescope itself, rings, cameras, finders, etc... ) are attached to a bar that is 43 mm (approximately 1.7 in) wide and 15 mm (0.6 in) high. The length varies depending on the size of the telescope to be attached. The sides of the bar are beveled at an angle of 15° from vertical, giving the bar a dovetail-shaped profile.

Here are some images of Vixen-style mounting bars:

[[File:Https---astrowiki.jmhastronomy.com-wikiimages-vr-220b-1s.png|200px|Top view of a Vixen-style dovetail bar.]]
[[File:Vixen-dovetail-red-bottom-view.png|200px|Bottom view of a Vixen-style dovetail bar.]]
[[File:Adm-vdup-11-1.png|200px|Another example of a Vixen-style bar.]]

Here is a mechanical drawing of the Vixen specification:

[[File:Vixen Profile.png|400px|Mechanical Drawing of a Vixen-style bar.]]

===Vixen Universal===

There is an older, alternative version of the Vixen dovetail that was originally designed for use with the Vixen Polaris German Equatorial Mount. The plate has some special notches cut for a more precise fit into the saddle. This plate is not found often, typically only on older telescopes. The notches are designed to fit the screws that clamp the bar onto the saddle. While the common Vixen and Losmandy style plates allow for the shifting of the payload forwards or backwards in the saddle along the length of the dovetail, the Vixen Universal plate does not allow this as the notches must be aligned to the clamping screws. This offers a more secure attachment, but, as previously stated, does not allow for shifting of the payload which is often useful for balancing the payload on the declination axis. In most cases, a modern standard Vixen saddle can accept the Vixen Universal plate, and vice-versa, but not always.

Here are some examples of the Vixen Universal dovetail bar:

[[File:OldStyleVixen.png|200px|Old-style Vixen dovetail bar.]]
[[File:VisenUniversalTop.png|200px|Vixen universal plate (old style), top view.]]
[[File:VixenUniversalBottom.png|200px|Vixen universal plate (old style), bottom view.]]

Here is a mechanical drawing of the Vixen Universal plate specification:

[[File:VixenUniversalSpec.png|400px|Vixen universal plate (old style), mechanical drawing.]]

==Losmandy==

A Losmandy-style dovetail plate, also referred to as the Losmandy D Series (to distinguish from the Losmandy V series, which are Vixen-style plates) serves the same function as a Vixen-style bar, but is wider and often used for heavier payloads. It also tends to provide more rigidity and stability. Aside from the overall width, one key difference between the Losmandy and Vixen style bars is that the dovetail portion of the Losmandy plate is typically fond underneath a wider portion for mounting the payload. The width of the dovetail, at its widest point, is approximately 3 inches wide, while the total width of the plate is roughly 4 inches wide. While the Vixen-style bar is 0.6 inches tall, the Losmandy is just short of 0.5 inches tall.

Due to the width and the fact that there is typically more surface area in contact with the saddle, they provide more stability and rigidity (as mentioned above). While you may often find telescopes with apertures of 8 inch (200 mm) or less frequently mounted on Vixen-style bars (though some users prefer the Losmandy plate), most larger telescopes will be found mounted on Losmandy-style plates.

These are some examples of the Losmandy D plate:

[[File:Losmandy-D-Top-View.png|200px|Losmandy D - top view]]
[[File:Losmandy-D-Top-View.png|200px|Losmandy D - top view]]
[[File:Losmandy-D-Bottom-View.png|200px|Losmandy D - bottom view]]
[[File:Losmandy-D-Actual.jpg|200px|Losmandy-made D plate (bottom view)]]

Here is a mechanical drawing of the Losmandy D specification:

[[File:Losmandy D Mechanical View.jpg|400px|Losmandy D mechanical drawing]]

==Celestron CGE==

Celestron, manufactured by the Synta Technology Corporation of Taiwan, sells most of its telescopes with a choice of mounting options. The first option they refer to as the CG-5 dovetail, named after the once-popular CG-5 mount. This is identical to the Vixen-style dovetail specification.

The other option they offer they refer to as the CGE dovetail, named after their CGE Pro mount, which used to be their premier German Equatorial Mount (GEM). Superficially it looks much like a Losmandy D plate, though it tends to have a curved portion while most Losmandy D plates rely on radius blocks for mounting larger scopes. However, while it looks similar, the specifications are slightly different and are not entirely compatible. A Losmandy-style dovetail saddle can usually handle a Celestron CGE plate, but a Celestron CGE saddle usually cannot handle a Losmandy-style plate.

Here are some images of Celestron CGE mounting plates:

[[File:CelestronCGEBottom.png|200px|Celestron CGE bottom view]]
[[File:CelestronCGETop.png|200px|Celestron CGE plate top view]]

Here is a mechanical drawing of the CGE specification:

[[File:CelestronSpecification.png|200px|A mechanical drawing of the Celestron CGE dovetail plate.]]

And here is a comparison of the Losmandy and Celestron dovetails:

[[File:Celestron Losmandy Comparison 1.jpg|600px|Comparison between CGE and Losmandy D profiles]]

==Synta==

The Synta dovetail mount, often referred to as the "Synta Shoe," is a smaller dovetail, similar in style to the Vixen, and primarily used for the mounting of accessory equipment, particularly finder scopes. Due to the fact that most items attached using this mounting method tend to be small, light accessories, many are manufactured from plastic, particularly through [https://en.wikipedia.org/wiki/Fused_filament_fabrication FDM] 3D printing methods using PLA, ABS, or PETG filaments.

The most common application, as mentioned, is for attaching finder scopes, but there are also synta mounts for things like [https://www.rigelsys.com/quikfinder.html Rigel Quickfinder] reflex sites, red-dot finders, counterweights, laser pointers, dew heater controllers, power distribution controllers, and computers like the [https://www.zwoastro.com/product/asiair-plus/ ZWO ASIAir].

Here are a few examples of Synta-style mounting hardware:

[[File:SyntaRedDot.png|200px|Red-dot finder on Synta mount.]]
[[File:SyntaDualMount.png|200px|Synta dual-mount adapter]]
[[File:SyntaRigelMount.png|200px|Synta mount for Rigel QuickFinder reflex site]]
[[File:SyntaComputerMount.png|200px|Synta mount for ASI Air or similar]]
[[File:SyntaFinderscope2.png|200px|Synta mount for finder scope, version 2]]
[[File:Synta finderscope mount.png|200px|Synta mount for finder scope]]
[[File:SyntaSaddle2.png|200px|Synta style saddle]]

Here is a mechanical drawing of the Synta specification:

[[File:SyntaMechanicalDrawing.png|200px|Synta saddle mechanical drawing]]

=Disclaimer=
Most or all of the images on this page are copied from third-party websites, mostly vendor sites. In particular I've used images taken from [https://agenaastro.com/ Agena Astro], [https://www.highpointscientific.com/ High Point Scientific], and [https://store-losmandy-com.3dcartstores.com/ Losmandy Astronomical Products]. If you are the owner or copyright holder of any of these images and would like me to remove them, please refer to my [[General Disclaimer|disclaimer page]] with contact information].

John's Astronomy And Astrophotography Wiki:General disclaimer

2026-07-23T18:00:19Z

Jmh921: Created page with "This site was created by John M. Haynes as a freely-accessible reference tool for amateur astronomy and astrophotography. There is no commercial interest involved here. Some..."

This site was created by John M. Haynes as a freely-accessible reference tool for amateur astronomy and astrophotography. There is no commercial interest involved here.

Some of the information and images may be copied from other sources. If you are the copyright holder of any such content and would like it taken down, please contact me directly at johnhaynes@jmhastronomy.com.

Dovetail Mounting Systems

2026-07-23T17:44:42Z

Jmh921:

Dovetail Mounting Systems

2026-07-23T17:41:36Z

Jmh921:

There are many ways of attaching a telescope to a mount. For some lower-end scopes, the scope is directly bolted to the mount head. For others, the scope's rings, if it uses rings, are directly bolted. For many high-end scopes and mounts, the mounting rings may also be directly bolted to the mount head. But for the majority of amateur telescopes in the mid and higher-end range, the mounting is done through a dovetail bar/plate and saddle method.

Over time, there have been several different specifications for these plates and saddles, with various manufacturers creating their own specifications for use with their equipment. However, over time, a few have become de-facto standards. The most popular such standards are known by the names of the companies that developed or at least popularized them: Vixen, Losmandy, and Synta.

Most dovetail bars are manufactured from extruded aluminum, though occasionally steel or other materials may be used. Aluminum typically provides sufficient strength while not adding significant weight. For lighter applications, some dovetails may be manufactured out of plastics, carbon fiber, or even wood, though these are much less common.

Note: ''The terms bar, plate, and rail are frequently used interchangeably to describe the portion which fits into the saddle, which will clamp down on the bar/plate/rail.''

Here is an example of a typical mounting saddle that would sit on top of the mount. This particular version is a dual-format saddle that can handle both Vixen and Losmandy-style dovetails.
[[File:DualSaddle.png|200px|Dual-mount saddle that can handle Vixen or Losmandy style dovetails.]]

==Vixen==

Using the Vixen-style system, the telescope payload (which may include the telescope itself, rings, cameras, finders, etc... ) are attached to a bar that is 43 mm (approximately 1.7 in) wide and 15 mm (0.6 in) high. The length varies depending on the size of the telescope to be attached. The sides of the bar are beveled at an angle of 15° from vertical, giving the bar a dovetail-shaped profile.

Here are some images of Vixen-style mounting bars:

[[File:Https---astrowiki.jmhastronomy.com-wikiimages-vr-220b-1s.png|200px|Top view of a Vixen-style dovetail bar.]]
[[File:Vixen-dovetail-red-bottom-view.png|200px|Bottom view of a Vixen-style dovetail bar.]]
[[File:Adm-vdup-11-1.png|200px|Another example of a Vixen-style bar.]]
[[File:Vixen Profile.png|200px|Mechanical Drawing of a Vixen-style bar.]]

===Vixen Universal===

There is an older, alternative version of the Vixen dovetail that was originally designed for use with the Vixen Polaris German Equatorial Mount. The plate has some special notches cut for a more precise fit into the saddle. This plate is not found often, typically only on older telescopes. The notches are designed to fit the screws that clamp the bar onto the saddle. While the common Vixen and Losmandy style plates allow for the shifting of the payload forwards or backwards in the saddle along the length of the dovetail, the Vixen Universal plate does not allow this as the notches must be aligned to the clamping screws. This offers a more secure attachment, but, as previously stated, does not allow for shifting of the payload which is often useful for balancing the payload on the declination axis. In most cases, a modern standard Vixen saddle can accept the Vixen Universal plate, and vice-versa, but not always.

Here are some examples of the Vixen Universal dovetail bar:

[[File:OldStyleVixen.png|200px|Old-style Vixen dovetail bar.]]
[[File:VisenUniversalTop.png|200px|Vixen universal plate (old style), top view.]]
[[File:VixenUniversalBottom.png|200px|Vixen universal plate (old style), bottom view.]]
[[File:VixenUniversalSpec.png|200px|Vixen universal plate (old style), mechanical drawing.]]

==Losmandy==

A Losmandy-style dovetail plate, also referred to as the Losmandy D Series (to distinguish from the Losmandy V series, which are Vixen-style plates) serves the same function as a Vixen-style bar, but is wider and often used for heavier payloads. It also tends to provide more rigidity and stability. Aside from the overall width, one key difference between the Losmandy and Vixen style bars is that the dovetail portion of the Losmandy plate is typically fond underneath a wider portion for mounting the payload. The width of the dovetail, at its widest point, is approximately 3 inches wide, while the total width of the plate is roughly 4 inches wide. While the Vixen-style bar is 0.6 inches tall, the Losmandy is just short of 0.5 inches tall.

Due to the width and the fact that there is typically more surface area in contact with the saddle, they provide more stability and rigidity (as mentioned above). While you may often find telescopes with apertures of 8 inch (200 mm) or less frequently mounted on Vixen-style bars (though some users prefer the Losmandy plate), most larger telescopes will be found mounted on Losmandy-style plates.

These are some examples of the Losmandy D plate:

[[File:Losmandy-D-Top-View.png|200px|Losmandy D - top view]]
[[File:Losmandy-D-Top-View.png|200px|Losmandy D - top view]]
[[File:Losmandy-D-Bottom-View.png|200px|Losmandy D - bottom view]]
[[File:Losmandy-D-Actual.jpg|200px|Losmandy-made D plate (bottom view)]]
[[File:Losmandy D Mechanical View.jpg|200px|Losmandy D mechanical drawing]]

==Celestron CGE==

Celestron, manufactured by the Synta Technology Corporation of Taiwan, sells most of its telescopes with a choice of mounting options. The first option they refer to as the CG-5 dovetail, named after the once-popular CG-5 mount. This is identical to the Vixen-style dovetail specification.

The other option they offer they refer to as the CGE dovetail, named after their CGE Pro mount, which used to be their premier German Equatorial Mount (GEM). Superficially it looks much like a Losmandy D plate, though it tends to have a curved portion while most Losmandy D plates rely on radius blocks for mounting larger scopes. However, while it looks similar, the specifications are slightly different and are not entirely compatible. A Losmandy-style dovetail saddle can usually handle a Celestron CGE plate, but a Celestron CGE saddle usually cannot handle a Losmandy-style plate.

Here are some images of Celestron CGE mounting plates:

[[File:CelestronCGEBottom.png|200px|Celestron CGE bottom view]]
[[File:CelestronCGETop.png|200px|Celestron CGE plate top view]]
[[File:CelestronSpecification.png|200px|A mechanical drawing of the Celestron CGE dovetail plate.]]
[[File:Celestron Losmandy Comparison 1.jpg|200px|Comparison between CGE and Losmandy D profiles]]

==Synta==

The Synta dovetail mount, often referred to as the "Synta Shoe," is a smaller dovetail, similar in style to the Vixen, and primarily used for the mounting of accessory equipment, particularly finder scopes. Due to the fact that most items attached using this mounting method tend to be small, light accessories, many are manufactured from plastic, particularly through [https://en.wikipedia.org/wiki/Fused_filament_fabrication FDM] 3D printing methods using PLA, ABS, or PETG filaments.

The most common application, as mentioned, is for attaching finder scopes, but there are also synta mounts for things like [https://www.rigelsys.com/quikfinder.html Rigel Quickfinder] reflex sites, red-dot finders, counterweights, laser pointers, dew heater controllers, power distribution controllers, and computers like the [https://www.zwoastro.com/product/asiair-plus/ ZWO ASIAir].

Here are a few examples of Synta-style mounting hardware:

[[File:SyntaRedDot.png|200px|Red-dot finder on Synta mount.]]
[[File:SyntaDualMount.png|200px|Synta dual-mount adapter]]
[[File:SyntaRigelMount.png|200px|Synta mount for Rigel QuickFinder reflex site]]
[[File:SyntaComputerMount.png|200px|Synta mount for ASI Air or similar]]
[[File:SyntaFinderscope2.png|200px|Synta mount for finder scope, version 2]]
[[File:Synta finderscope mount.png|200px|Synta mount for finder scope]]
[[File:SyntaMechanicalDrawing.png|200px|Synta saddle mechanical drawing]]
[[File:SyntaSaddle2.png|200px|Synta style saddle]]

Dovetail Mounting Systems

2026-07-23T17:28:19Z

Jmh921: /* Vixen */

There are many ways of attaching a telescope to a mount. For some lower-end scopes, the scope is directly bolted to the mount head. For others, the scope's rings, if it uses rings, are directly bolted. For many high-end scopes and mounts, the mounting rings may also be directly bolted to the mount head. But for the majority of amateur telescopes in the mid and higher-end range, the mounting is done through a dovetail bar/plate and saddle method.

Over time, there have been several different specifications for these plates and saddles, with various manufacturers creating their own specifications for use with their equipment. However, over time, a few have become de-facto standards. The most popular such standards are known by the names of the companies that developed or at least popularized them: Vixen, Losmandy, and Synta.

Note: ''The terms bar, plate, and rail are frequently used interchangeably to describe the portion which fits into the saddle, which will clamp down on the bar/plate/rail.''

==Vixen==

Using the Vixen-style system, the telescope payload (which may include the telescope itself, rings, cameras, finders, etc... ) are attached to a bar that is 43 mm (approximately 1.7 in) wide and 15 mm (0.6 in) high. The length varies depending on the size of the telescope to be attached. The sides of the bar are beveled at an angle of 15° from vertical, giving the bar a dovetail-shaped profile.

[[File:Https---astrowiki.jmhastronomy.com-wikiimages-vr-220b-1s.png|200px|Top view of a Vixen-style dovetail bar.]]
[[File:Vixen-dovetail-red-bottom-view.png|200px|Bottom view of a Vixen-style dovetail bar.]]
[[File:Adm-vdup-11-1.png|200px|Another example of a Vixen-style bar.]]
[[File:Vixen Profile.png|200px|Mechanical Drawing of a Vixen-style bar.]]

===Vixen Universal===

There is an older, alternative version of the Vixen dovetail that was originally designed for use with the Vixen Polaris German Equatorial Mount. The plate has some special notches cut for a more precise fit into the saddle. This plate is not found often, typically only on older telescopes. The notches are designed to fit the screws that clamp the bar onto the saddle. While the common Vixen and Losmandy style plates allow for the shifting of the payload forwards or backwards in the saddle along the length of the dovetail, the Vixen Universal plate does not allow this as the notches must be aligned to the clamping screws. This offers a more secure attachment, but, as previously stated, does not allow for shifting of the payload which is often useful for balancing the payload on the declination axis.

[[File:OldStyleVixen.png|200px|Old-style Vixen dovetail bar.]]
[[File:VisenUniversalTop.png|200px|Vixen universal plate (old style), top view.]]
[[File:VixenUniversalBottom.png|200px|Vixen universal plate (old style), bottom view.]]
[[File:VixenUniversalSpec.png|200px|Vixen universal plate (old style), mechanical drawing.]]

==Losmandy==

A Losmandy-style dovetail plate, also referred to as the Losmandy D Series (to distinguish from the Losmandy V series, which are Vixen-style plates) serves the same function as a Vixen-style bar, but is wider and often used for heavier payloads. It also tends to provide more rigidity and stability. Aside from the overall width, one key difference between the Losmandy and Vixen style bars is that the dovetail portion of the Losmandy plate is typically fond underneath a wider portion for mounting the payload. The width of the dovetail, at its widest point, is approximately 3 inches wide, while the total width of the plate is roughly 4 inches wide. While the Vixen-style bar is 0.6 inches tall, the Losmandy is just short of 0.5 inches tall.

Due to the width and the fact that there is typically more surface area in contact with the saddle, they provide more stability and rigidity (as mentioned above). While you may often find telescopes with apertures of 8 inch (200 mm) or less frequently mounted on Vixen-style bars (though some users prefer the Losmandy plate), most larger telescopes will be found mounted on Losmandy-style plates.

[[File:Losmandy-D-Top-View.png|200px|Losmandy D - top view]]
[[File:Losmandy-D-Top-View.png|200px|Losmandy D - top view]]
[[File:Losmandy-D-Bottom-View.png|200px|Losmandy D - bottom view]]
[[File:Losmandy-D-Actual.jpg|200px|Losmandy-made D plate (bottom view)]]
[[File:Losmandy D Mechanical View.jpg|200px|Losmandy D mechanical drawing]]

==Celestron CGE==

Celestron, manufactured by the Synta Technology Corporation of Taiwan, sells most of its telescopes with a choice of mounting options. The first option they refer to as the CG-5 dovetail, named after the once-popular CG-5 mount. This is identical to the Vixen-style dovetail specification.

The other option they offer they refer to as the CGE dovetail, named after their CGE Pro mount, which used to be their premier German Equatorial Mount (GEM). Superficially it looks much like a Losmandy D plate, though it tends to have a curved portion while most Losmandy D plates rely on radius blocks for mounting larger scopes. However, while it looks similar, the specifications are slightly different and are not entirely compatible. A Losmandy-style dovetail saddle can usually handle a Celestron CGE plate, but a Celestron CGE saddle usually cannot handle a Losmandy-style plate.

[[File:CelestronCGEBottom.png|200px|Celestron CGE bottom view]]
[[File:CelestronCGETop.png|200px|Celestron CGE plate top view]]
[[File:CelestronSpecification.png|200px|A mechanical drawing of the Celestron CGE dovetail plate.]]
[[File:Celestron Losmandy Comparison 1.jpg|200px|Comparison between CGE and Losmandy D profiles]]

==Synta==

The Synta dovetail mount, often referred to as the "Synta Shoe," is a smaller dovetail, similar in style to the Vixen, and primarily used for the mounting of accessory equipment, particularly finder scopes. Due to the

[[File:DualSaddle.png|200px|Dual-mount saddle that can handle Vixen or Losmandy style dovetails.]]
[[File:SyntaRedDot.png|200px|Red-dot finder on Synta mount.]]
[[File:SyntaDualMount.png|200px|Synta dual-mount adapter]]
[[File:SyntaRigelMount.png|200px|Synta mount for Rigel QuickFinder reflex site]]
[[File:SyntaComputerMount.png|200px|Synta mount for ASI Air or similar]]
[[File:SyntaFinderscope2.png|200px|Synta mount for finder scope, version 2]]
[[File:Synta finderscope mount.png|200px|Synta mount for finder scope]]
[[File:SyntaMechanicalDrawing.png|200px|Synta saddle mechanical drawing]]
[[File:SyntaSaddle2.png|200px|Synta style saddle]]

File:VixenUniversalSpec.png

2026-07-23T17:21:41Z

Jmh921: Vixen universal plate (old style), mechanical drawing.

== Summary ==
Vixen universal plate (old style), mechanical drawing.

File:VixenUniversalBottom.png

2026-07-23T17:21:14Z

Jmh921: Vixen universal plate (old style), bottom view.

== Summary ==
Vixen universal plate (old style), bottom view.

File:VisenUniversalTop.png

2026-07-23T17:20:51Z

Jmh921: Vixen universal plate (old style), top view.

== Summary ==
Vixen universal plate (old style), top view.

File:CelestronSpecification.png

2026-07-23T17:08:29Z

Jmh921: A mechanical drawing of the Celestron CGE dovetail plate.

== Summary ==
A mechanical drawing of the Celestron CGE dovetail plate.

File:DualSaddle.png

2026-07-23T17:00:08Z

Jmh921: Dual-mount saddle that can handle Vixen or Losmandy style dovetails.

== Summary ==
Dual-mount saddle that can handle Vixen or Losmandy style dovetails.

File:OldStyleVixen.png

2026-07-23T16:59:34Z

Jmh921: Old-style Vixen dovetail bar.

== Summary ==
Old-style Vixen dovetail bar.

File:SyntaRedDot.png

2026-07-23T16:59:01Z

Jmh921: Red-dot finder on Synta mount.

== Summary ==
Red-dot finder on Synta mount.

File:SyntaDualMount.png

2026-07-23T16:58:25Z

Jmh921: Synta dual-mount adapter

== Summary ==
Synta dual-mount adapter

File:SyntaRigelMount.png

2026-07-23T16:57:58Z

Jmh921: Synta mount for Rigel QuickFinder reflex site

== Summary ==
Synta mount for Rigel QuickFinder reflex site

File:SyntaComputerMount.png

2026-07-23T16:57:22Z

Jmh921: Synta mount for ASI Air or similar

== Summary ==
Synta mount for ASI Air or similar

File:SyntaFinderscope2.png

2026-07-23T16:56:58Z

Jmh921: Synta mount for finder scope, version 2

== Summary ==
Synta mount for finder scope, version 2

File:Synta finderscope mount.png

2026-07-23T16:56:34Z

Jmh921: Synta mount for finder scope

== Summary ==
Synta mount for finder scope

File:SyntaMechanicalDrawing.png

2026-07-23T16:56:02Z

Jmh921: Synta saddle mechanical drawing

== Summary ==
Synta saddle mechanical drawing

File:SyntaSaddle2.png

2026-07-23T16:55:36Z

Jmh921: Synta style saddle

== Summary ==
Synta style saddle

File:Celestron Losmandy Comparison 1.jpg

2026-07-23T16:54:45Z

Jmh921: Comparison between CGE and Losmandy D profiles

== Summary ==
Comparison between CGE and Losmandy D profiles

File:CelestronCGEBottom.png

2026-07-23T16:54:04Z

Jmh921: Celestron CGE bottom view

== Summary ==
Celestron CGE bottom view

File:CelestronCGETop.png

2026-07-23T16:53:29Z

Jmh921: Celestron CGE plate top view

== Summary ==
Celestron CGE plate top view

File:Losmandy D Mechanical View.jpg

2026-07-23T16:26:48Z

Jmh921: Mechanical drawing of a Losmandy D plate.

== Summary ==
Mechanical drawing of a Losmandy D plate.
== Licensing ==
{{Unknown_copyright}}

File:Losmandy-D-Actual.jpg

2026-07-23T16:25:20Z

Jmh921: An actual Losmandy-made D plate

== Summary ==
An actual Losmandy-made D plate

File:Losmandy-D-Bottom-View.png

2026-07-23T16:23:57Z

Jmh921: Losmandy D - bottom view

== Summary ==
Losmandy D - bottom view
== Licensing ==
{{Unknown_copyright}}

File:Losmandy-D-Top-View.png

2026-07-23T16:22:38Z

Jmh921: A Losmandy-style dovetail plate (top view)

== Summary ==
A Losmandy-style dovetail plate (top view)
== Licensing ==
{{Unknown_copyright}}

File:Vixen Profile.png

2026-07-23T16:06:19Z

Jmh921: A mechanical drawing for a Vixen-style dovetail bar.

== Summary ==
A mechanical drawing for a Vixen-style dovetail bar.
== Licensing ==
{{Unknown_copyright}}

File:Adm-vdup-11-1.png

2026-07-23T16:04:51Z

Jmh921: Another example of a Vixen-style dovetail bar, this one manufactured by ADM.

== Summary ==
Another example of a Vixen-style dovetail bar, this one manufactured by ADM.
== Licensing ==
{{Unknown_copyright}}

File:Vixen-dovetail-red-bottom-view.png

2026-07-23T16:03:14Z

Jmh921: A Vixen-style dovetail bar, bottom-view.

== Summary ==
A Vixen-style dovetail bar, bottom-view.
== Licensing ==
{{Unknown_copyright}}

File:Https---astrowiki.jmhastronomy.com-wikiimages-VixenDovetail Red Bottom.webp

2026-07-23T16:00:29Z

Jmh921: A Vixen-style dovetail bar, bottom-view.

== Summary ==
A Vixen-style dovetail bar, bottom-view.
== Licensing ==
{{Unknown_copyright}}

Dovetail Mounting Systems

2026-07-23T15:58:26Z

Jmh921: /* Vixen */

Dovetail Mounting Systems

2026-07-23T15:57:12Z

Jmh921:

File:Https---astrowiki.jmhastronomy.com-wikiimages-vr-220b-1s.png

2026-07-23T15:55:32Z

Jmh921: An example of a Vixen-style dovetail bar (Top-View)

== Summary ==
An example of a Vixen-style dovetail bar (Top-View)
== Licensing ==
{{Unknown_copyright}}

Dovetail Mounting Systems

2026-07-23T15:53:21Z

Jmh921:

Dovetail Mounting Systems

2026-07-23T15:50:40Z

Jmh921: Created page with "There are many ways of attaching a telescope to a mount. For some lower-end scopes, the scope is directly bolted to the mount head. For others, the scope's rings, if it uses..."

Template:Documentation

2026-02-05T03:51:11Z

Jmh921: Created page with "{{#invoke:documentation|main|_content={{ {{#invoke:documentation|contentTitle}}}}}}<noinclude>  </noinclude>"

{{#invoke:documentation|main|_content={{ {{#invoke:documentation|contentTitle}}}}}}<noinclude>

</noinclude>

Template:Coord

2026-02-05T03:50:43Z

Jmh921: Created page with "<includeonly>{{#invoke:Coordinates|coord}}</includeonly><noinclude> {{Documentation}}  </noinclude>"

<includeonly>{{#invoke:Coordinates|coord}}</includeonly><noinclude>
{{Documentation}}

</noinclude>

Sandbox

2026-02-05T03:43:46Z

Jmh921: Created page with "This is a sandbox page for testing formatting {{coord|65|31|N|95|56|E|type:landmark_scale:300000|display=inline,title}}"

This is a sandbox page for testing formatting

{{coord|65|31|N|95|56|E|type:landmark_scale:300000|display=inline,title}}

Common Equipment Standards

2025-06-09T02:41:43Z

Jmh921: Created page with "This page is intended to hold information about commonly used standards for equipment used by amateur astronomers. ==Eyepiece Formats== There are three common formats for ey..."

This page is intended to hold information about commonly used standards for equipment used by amateur astronomers.

==Eyepiece Formats==

There are three common formats for eyepieces based on the diameter of the eyepiece's barrel flange and the focuser's receptacle. These are typically described using imperial standard measures.

0.965 inch

1.25 inch

2 inch

==Threads==

{| class="wikitable" style="margin:auto"
|+ Threads commonly found on astronomical equipment <ref>https://astrobasics.de/en/components/thread-types/</ref>
|-
! Common Name !! Specification* !! Common Uses !! Notes
|-
| T2 || M42x0.75 || (Need info here) ||
|-
| SCT Thread || 2"x1/24" (50.8x1.058 mm) || SCT visual backs || Typically found on the back of Schmidt-Cassegrain telescopes for attaching a visual back.
|-
| C-Mount || 1"x1/32" (25.4x0.794 mm) || Camera lens mounts || Often used to attach lenses to cameras where a proprietary connection is not used (e.g. Nikon or Canon lens mounts). Usually has a back-focus distance of 17.526 mm.
|-
| CS-Mount || 1"x1/32" (25.4x0.794 mm) || Camera lens mounts || Similar to C-Mount, but usually has a back-focus distance of 12.526 mm.
|-
| 1.25" Filter Thread || M28.5x0.5 || Commonly used for attaching filters to 1.25" eyepieces. || Some manufacturers use a 0.6 thread pitch.
|-
| 2" Filter Thread || M48x0.6 || Commonly used for attaching filters to 2" eyepieces. || Some manufacturers use a 0.75 thread pitch.
|-
| Camera Tripod Thread || 1/4"x20 (6.35x1.27 mm) || Attaching cameras to tripods || Found on most DSLR and other consumer cameras as well as many small telescopes and other items.
|-
| Larger Camera Tripod Thread || 3/8"x16 (9.53x1.5875 mm) || Attaching larger cameras to tripod || Commonly found on medium and large format cameras. Also used by the ZWO SeeStar Smart Telescopes.
|}

* If the specification is not normally given in metric, metric is included in parentheses.

Tutorials

2025-04-28T18:38:52Z

Jmh921: Created page with "This page is intended to hold links to a variety of tutorials for amateur astronomy and astrophotography. If you have a link to add and do not have access to editing content,..."

This page is intended to hold links to a variety of tutorials for amateur astronomy and astrophotography. If you have a link to add and do not have access to editing content, please contact the manager of this site at johnhaynes@jmhastronomy.com [mailto:johnhaynes@jmhastronomy.com?Subject=Requesting%20changes%20to%20AstroWiki%20Tutorials%20Page johnhaynes@jmhastronomy.com]

=General Astronomy=

=Astrophotography=

==General==

[https://naplab.com/guides/astrophotography-guide/ Sleeping Under the Stars: A Beginner’s Guide to Stargazing and Astrophotography]

==Equipment==

==Image Capture==

==Processing==

===Pixinsight===

[https://www.pixinsight.com/tutorials/ Tutorials on the Pixinsight website]

[https://www.mastersofpixinsight.com/ Masters of Pixinsight]

[https://web.archive.org/web/20220315073829/https://www.lightvortexastronomy.com/ Light Vortex Astronomy] (The site is no longer active, but is available via the Wayback Machine).

=Amateur Telescope Making (ATM)=

[https://stellafane.org/tm/index.html Stellafane's Telescope Making Site]

Refractor Telescope

2025-01-30T16:09:58Z

Jmh921: Created page with "A refracting telescope, or refractor, is a type of telescope that uses lenses to collect and focus light. Refractors were the first telescopes constructed with their history..."

A refracting telescope, or refractor, is a type of telescope that uses lenses to collect and focus light. Refractors were the first telescopes constructed with their history going back to at least 1608.<ref>There is some debate as to who invented the telescope and when, but the first documented reference is a patent application submitted to the States General of the Netherlands by Hans Lippershey, a spectacle maker living in Middleburg. However, the patent was rejected as the invention was considered not a new innovation. This strongly suggests that other telescopes had been made by that time.</ref>

Refracting telescopes have one or more lenses mounted at the front-end of the tube, known as the objective <ref>These are sometimes mistakenly referred to as the "primary," but the correct term is "objective." Primary is the term used for the main mirror in a reflecting or catadioptric telescope.</ref>, and one or more lenses placed at the [[focal point]] of the telescope, referred to as the eyepiece.

==Advantages and Disadvantages==
The primary advantages of a refractor include:<ref>https://personal.math.ubc.ca/~cass/courses/m309-03a/m309-projects/wong/pro.html</ref>
* Superior revolving power per inch of aperture
* Superior performance in inferior conditions and steadier images
* No reflections or interruption of light path
* Rarely need [[collimation]] and minimal maintenance
* The longer focal ratios that are typical of most refractors perform better than other designs with longer focus and simpler eyepieces

The main disadvantages of refractors are:<ref>https://personal.math.ubc.ca/~cass/courses/m309-03a/m309-projects/wong/pro.html</ref>
* A higher price per inch of aperture compared to reflectors and (usually) catadioptrics.
* [[Chromatic Aberration]], an optical aberration that causes
* Long focal ratios can mean that the instrument is cumbersome

==notes for ongoing development==

A refracting telescope's main advantages include: superior image quality with excellent color correction, minimal maintenance due to a sealed optical tube, ease of use with fewer moving parts, a stable and uninterrupted light path, near-permanent optical alignment, and better performance in poor viewing conditions, making them ideal for planetary observation and astrophotography where sharp details are crucial; however, they can be more expensive to manufacture due to the challenges of producing large, high-quality lenses and may suffer from chromatic aberration if not properly designed.
Key advantages of a refracting telescope:
High image quality:
Refractors generally produce sharp, detailed images with good color fidelity, especially when using high-quality apochromatic lenses.
Low maintenance:
With a sealed optical tube, refractors require minimal cleaning and adjustments to maintain alignment.
Ease of use:
Simple design with fewer moving parts, making them user-friendly for beginners.
No central obstruction:
Unlike reflectors, refractors have no central mirror obstruction, allowing for better contrast in the image.
Portable and compact:
Can be relatively lightweight and easy to transport, making them suitable for travel.
Wide field of view:
Some refractor designs can offer a wider field of view compared to certain reflectors.

Astronomy Clubs

2025-01-29T19:01:42Z

Jmh921: /* United States */

An astronomy club or astronomical society is an organization, usually composed of amateur astronomers, for the advancement, enjoyment, and participation in astronomy.

Generally speaking, astronomy clubs are focused on education of the public toward astronomy and astronomy-related subjects and the promotion of astronomy as a hobby. While the particular activities and focus of such clubs varies from group to group, they are all generally interested in advancing awareness and sharing in the wonder of astronomy.

Below you can find a list of astronomy clubs around the world. Please feel free to add your own if it is not listed.

=Why Join a Club=

As mentioned above, the specifics vary from club to club, however, there are common trends among most clubs.

Most clubs conduct regular, most often monthly, meetings. For most clubs this includes a discussion of club business, but the focal point is some form of presentation on a specific topic. The topic may include such topics as using, maintaining, or constructing telescopes, techniques concerning astrophotography, or discussions of visible objects in the night, or it may be a more broadly-based discussion of astronomy, such as discussing the life cycle of stars, recent discoveries in exoplanets, the physics behind star formation, or even community-related topics such as light pollution and what can be done to improve it. Some clubs have multiple sessions aimed at beginners and more advanced members. Many clubs also conduct workshops and training classes for observing and using telescopes.

===Dark Sites===

While most clubs conduct meetings like this, they tend to be more centered around observing activities. In such clubs, many members own telescopes and, in fact, may have joined in order to learn more about using and maintaining their telescope. To this end, many clubs either own or have access to a piece of land reserved as an observing site, or a "dark site." A [[Dark Site]] is a place reserved for observing where light pollution is better regulated. Most such places are outside of major cities, but within relatively easy driving distance. They typically are shielded from major roads by walls, fences, trees, and/or bushes and usage of light, particularly white light, during observing times is generally restricted (see [[Light Discipline]] for more information).

Not all clubs have access to their own dark site. However, in those cases, members of the club will usually have scouted out areas that are generally conducive for observing activities. Such locations are often found in municipal parks in a city or town, or in state parks or nature preserves outside of town. The primary features of such sites are little traffic/stray light and skies with noticeably less light pollution than in the city.

===Star Parties===
Many clubs also conduct regular star parties. A [[star party]] is a gathering, often at a club's dark site, where those who have telescopes bring them out and the assembled members and guests spend an evening observing. Most telescope owners are generally happy to let others look through their telescope, and many are happy to talk all about the equipment being used and the object(s) being viewed. Star parties may simply be gatherings of members or may have a focus on outreach. Many clubs also offer to conduct them for schools and community organizations.

Those clubs that own their own dark site or have access to one in association with a school, business, or other organization sometimes also have their own observatory or access to an observatory, at which one or more telescopes are permanently mounted in a facility designed for the purpose. These telescopes are often larger and/or more expensive and complex than most members would have the ability to purchase, though sometimes they're more modest systems. Clubs that have observatories typically have a process for members to be able to access them.

Star parties are also a great way for those who don't have telescopes to learn more about them before they purchase. Attending a star party will usually allow a member to look through several different types of telescope and give him or her a chance to talk to the owner about the experience of owning a particular type of telescope.

===Loaner Telescopes===

Some clubs also have club-owned equipment for users to borrow. Loaner scope programs often provide access to fairly common telescopes to members and may serve as a way for members to try out different types of telescope before they spend the money themselves on their own.

===Astronomical League===

In the United States, most local clubs are also members of the [https://www.astroleague.org/ Astronomical League], or AL, which serves as something of a parent organization for astronomy clubs and societies in the US as well as offering "member at large" membership to those not part of a specific club and those outside of the United States. Among the benefits of membership in the AL is access to their [https://www.astroleague.org/observing.html Observing Programs]. The AL Observing Programs are designed to help provide a purpose and direction to observations (giving those who participate a sense of a mission to accomplish). Many such programs award a certificate and/or pin to commemorate the observer's achievement. For example, those who complete the [https://www.astroleague.org/al/obsclubs/messier/mess.html Messier Observing Program] will get a certificate after observing 70 of the 110 objects in the [[Messier Catalog]], and observation of the full list of 110 will earn a certificate and pin. To qualify, the observations must be logged with specific information and this information must be approved (either by a local club official or by the national coordinator).

===Club Dues===

Most clubs in the United States are 501(c)(3) non-profit organizations. However, most do charge annual membership dues to maintain club equipment and facilities and to do such things as pay for guest speakers and awards.

In the US, at the time of this writing (October of 2019), club dues for most local clubs cost $50 per year or less, with many being significantly less. Many clubs also prorate club membership depending on the month in which a member joins.

For example:

*The [http://www.astronomyhouston.org Houston Astronomical Society] in Houston, TX, currently charges annual dues of $36 per year for a standard membership (there are also senior, student, and family rates). If a member joins in October, they would pay only $9 (a rate of $3 per month times 3 months) for the remainder of the year, then pay the full $36 at the beginning of the following year for that year's membership.

*The [http://www.rivastro.org/index.php Riverside Astronomical Society] in Riverside, CA, has an introductory rate of $20 for individuals, with a renewal rate of $40, and offering "Patron" memberships of $100, $200, and $300 per year for Bronze, Silver, and Gold memberships (respectively).

Not all clubs prorate, but it is fairly common. Other clubs handle dues on a rotating-year model (e.g. if you join in October, your membership is good through the next October, at which time you must renew). Contact your local club for specifics concerning dues.

For clubs that are members of the Astronomical League, typically a portion of your regular dues is used to pay your membership in the AL. The cost of AL membership for members of member clubs is typically significantly less than membership-at-large.

For clubs outside of the United States, the cost will vary.

=Lists of Clubs=

===United States===

*[https://www.astroleague.org/astronomy-clubs-usa-state Astronomical League] The Astronomical League is a collection of clubs throughout the United States. The link provided will allow you to find a club near you within your state.

*[https://nightsky.jpl.nasa.gov/club-map.cfm Night Sky Network] The Night Sky Network, or NSN, is a partnership between NASA/JPL, The Astronomical Society of the Pacific, numerous individual astronomy clubs and societies, the Institute for Learning Innovation, and several other organizations with an interest in science, astronomy, and education. They include a listing of clubs and events, searchable by Zip Code.

*[https://www.go-astronomy.com/astro-club-search.htm Go Astronomy Club Lists] Go Astronomy is a website with a variety of resources for astronomy, and worth a look for many reasons. They also include a very extensive directory of clubs, societies, observatories, and planetariums, mostly n the United States.

*[https://www.skyandtelescope.com/astronomy-clubs-organizations/ Sky And Telescope] Sky And Telescope magazine's online site also has a database of clubs, organizations, museums, observatories, and more. Their content is focused on the United States, but includes international content as well. Their database does not appear to be particularly well curated, however, and club listings may be out of date.

{| class="wikitable sortable"
|+ '''List of Local Astronomy Clubs In the United States:'''<ref>https://www.astroleague.org/astronomy-clubs-usa-state/</ref>
|-
! style="text-align:left; width: 30%" | Society Name
!! style="text-align:left;" | City
!! style="text-align:left;" | State
!! style="text-align:left;" | Address
!! style="text-align:left;" | Website
!! style="text-align:left;" | Facebook Page
!! style="text-align:left;" | Member of the Astronomical Legue
|-
| Auburn Astronomical Society || Auburn || Alabama || || http://www.auburnastro.org/ || || ''✓''
|-
| East Valley Astronomy Club || Mesa || Arizona || P.O. Box 2202 || http://www.evaconline.org || || ''✓''
|-
| Prescott Astronomy Club || Prescott || Arizona || Prescott Astronomy Club186 E. Sheldon St. #1122 || https://prescottastronomyclub.org/ || || ''✓''
|-
| Phoenix Astronomical Society, Inc. || Scottsdale || Arizona || 7979 E Princess Dr || http://www.pasaz.org || || ''✓''
|-
| Huachuca Astronomy Club || Sierra Vista || Arizona || P.O Box 922 || http://www.hacastronomy.org || || ''✓''
|-
| Tucson Amateur Astronomy Association || Tucson || Arizona || P. O. Box 41254 || http://www.tucsonastronomy.org || || ''✓''
|-
| Sugar Creek Astronomical Society || Bentonville || Arkansas || || || || ''✓''
|-
| Kern County Astronomical Society || Bakersfield || California || 5501 Stockdale Hwy #10241 || https://www.kernastro.org || || ''✓''
|-
| Aerospace Employees Association Astronomy Club || El Segundo || California || 2310 E El Segundo Blvd || || || ''✓''
|-
| Astronomers of Humboldt || Eureka || California || P.O. Box 351 || https://www.astrohum.org || || ''✓''
|-
| Temecula Valley Astronomers || Murrieta || California || P.O. Box1292 || https://www.temeculavalleyastronomers.com || || ''✓''
|-
| South Bay Astronomical Society || Redondo Beach || California || P.O. Box 1244 || https://www.sbastro.net || || ''✓''
|-
| San Diego Astronomy Association || San Diego || California || PO Box 23215 || https://sdaa.org/ || || ''✓''
|-
| TAC - AL (The Astronomy Connection) || San Jose || California || || || || ''✓''
|-
| Bear Valley Springs Astronomy Club || Tehachapi || California || 23871 Lakeview Dr. || https://www.bvsac.org || || ''✓''
|-
| Tulare Astronomical Association || Tulare || California || 1062 N. A. St. || https://tulareastro.org/ || || ''✓''
|-
| Mt. Shasta Stargazers || Weed || California || 134 Shasta Cove N || https://www.mtshastastargazers.com || || ''✓''
|-
| Colorado Springs Astronomical Society || Colorado Springs || Colorado || PO Box 16318 || http://www.csastro.org || || ''✓''
|-
| Denver Astronomical Society || Denver || Colorado || P.O. Box 102738 || http://www.denverastro.org || || ''✓''
|-
| Gunnison Valley Observatory || Gunnison || Colorado || P. O. Box 1227 || https://www.gunnisonvalleyobservatory.org/ || || ''✓''
|-
| Longmont Astronomical Society || Longmont || Colorado || P.O. Box 806 || https://www.longmontastro.org || || ''✓''
|-
| Black Canyon Astronomical Society || Montrose || Colorado || 27 N. Willerup Ave || https://blackcanyonastronomy.com/ || || ''✓''
|-
| Shoreline Astronomical Society || Madison || Connecticut || 83 Wildcat Rd || https://shorelineastronomicalsociety.blogspot.com/ || || ''✓''
|-
| Litchfield Hills Amateur Astronomy Club || Morris || Connecticut || 211 West St || https://www.LHastro.org || || ''✓''
|-
| Delaware Astronomical Society || Greenville || Delaware || Mount Cuba Obervatory1610 Hillside Mill Rd. || https://www.delastro.org || || ''✓''
|-
| National Capital Astronomers || Davidson || District of Columbia || 3804 Wayson Road || http://www.capitalastronomers.org || || ''✓''
|-
| Local Group of Deep Sky Observers || Ellenton || Florida || 5610 32nd Ave E. || http://www.LGDSO.com || || ''✓''
|-
| Alachua Astronomy Club || Gainesville || Florida || 2603 NW 13th St., #161 || || || ''✓''
|-
| Northeast Florida Astronomical Society || Jacksonville || Florida || P.O. Box 5432 || http://www.nefas.org || || ''✓''
|-
| Brevard Astronomical Society || Melbourne || Florida || PO Box 410092 || https://www.brevardastro.org/ || || ''✓''
|-
| Everglades Astronomical Society || Naples || Florida || 270 Naples Cove Drive, Unit 3206 || https://evergladesastronomicalsociety.org/ || || ''✓''
|-
| Moonstruck Astronomy Club || Ocala || Florida || || https://moonstruckastronomyclub.org/ || || ''✓''
|-
| Central Florida Astronomical Society, Inc. || Oviedo || Florida || P.O. Box 620907 || https://cfas.org || || ''✓''
|-
| Escambia Amateur Astronomers' Assn. || Pensacola || Florida || || https://sites.google.com/view/escambiaastronomers || || ''✓''
|-
| Tallahassee Astronomical Society || Tallahassee || Florida || PO Box 824 || http://www.tallystargazers.org/ || || ''✓''
|-
| Astronomical Society of the Palm Beaches || West Palm Beach || Florida || P.O. Box 19652 || https://www.astropalmbeach.org || || ''✓''
|-
| Atlanta Astronomy Club, Inc. || Altanta || Georgia || P. O. Box 76155 || http://www.AtlantaAstronomy.org || || ''✓''
|-
| Flint River Astronomy Club || Brooks || Georgia || 788 Rising Star Rd || http://www.flintriverastronomy.org/ || || ''✓''
|-
| Hawaiian Astronomical Society || Honolulu || Hawaii || P.O. Box 17671 || http://www.hawastsoc.org/ || || ''✓''
|-
| Haleakala Amateur Astronomers || Kula || Hawaii || || || || ''✓''
|-
| Boise Astronomical Society || Boise || Idaho || P.O. Box 7002 || http://www.boiseastro.org || || ''✓''
|-
| Idaho Falls Astronomical Society || Idaho Falls || Idaho || P.O. Box 50262 || http://ifastro.org/ || || ''✓''
|-
| Pocatello Astronomical Society || Pooctello || Idaho || || https://pocatelloastronomicalsociety.com/ || || ''✓''
|-
| Champaign-Urbana Astronomical Society || Champaign || Illinois || Staerkel Planetarium/Parkland College2400 West Bradley Avenue || https://www.cuas.org || || ''✓''
|-
| Rockford Amateur Astronomers, Inc. || Loves Park || Illinois || 6691 Squire Ln. || || || ''✓''
|-
| Twin City Amateur Astronomers, Inc. || Normal || Illinois || 1109 N. Linden St. || https://www.tcaa.club/ || || ''✓''
|-
| Popular Astronomy Club || Orion || Illinois || 11 Deer Run Road || https://www.popularastronomyclub.org/ || || ''✓''
|-
| Northwest Suburban Astronomers || Palatine || Illinois || PO Box 95462 || https://www.nsaclub.org/ || || ''✓''
|-
| Peoria Astronomical Society || Peoria || Illinois || PO BOX 10111 || http://www.astronomical.org || || ''✓''
|-
| Fox Valley Sky Watchers || Sleepy Hollow || Illinois || 164 Hilltop Lane || || || ''✓''
|-
| Evansville Astronomical Society || Evansville || Indiana || P.O. Box 3474 || http://evansvilleastro.org/ || || ''✓''
|-
| Fort Wayne Astronomical Society || Fort Wayne || Indiana || PO Box 11093 || https://www.fortwayneastronomicalsociety.com/ || || ''✓''
|-
| Indiana Astronomical Society || Mooresville || Indiana || P.O. Box 703 || http://www.iasindy.org || || ''✓''
|-
| Ames Area Amateur Astronomers || Ames || Iowa || P.O. Box 1961 || http://www.amesastronomers.org/ || || ''✓''
|-
| Des Moines Astronomical Society, Inc || Des Moines || Iowa || P.O. Box 111 || http://www.dmastronomy.com || || ''✓''
|-
| Black Hawk Astronomy Club || Waterloo || Iowa || 503 South Street || || || ''✓''
|-
| Southeastern Iowa Astronomy Club || West Burlington || Iowa || PO Box 14 || || || ''✓''
|-
| Kansas Astronomical Observers || Goddard || Kansas || 25000 W 39th S || http://www.kaowichita.com/ || || ''✓''
|-
| Astronomy Associates of Lawrence || Lawrence || Kansas || 1082 Malott Hall, 1251 Wescoe Hall Drive || https://astronaal.ku.edu/aboutaal || || ''✓''
|-
| Northeast Kansas Amateur Astronomer's League, Inc. || Topeka || Kansas || P.O. Box 951 || http://www.nekaal.org || || ''✓''
|-
| West Kentucky Amateur Astronomers || Golden Pond || Kentucky || West Kentucky Amateur Astronomers238 Visitor Center Drive || || https://www.facebook.com/groups/496426749191848 || ''✓''
|-
| Baton Rouge Astronomical Society || Baton Rouge || Louisiana || || http://www.brastro.org/ || || ''✓''
|-
| Shreveport-Bossier Astronomical Society, Inc. || Shreveport || Louisiana || 353 Ockley Drive || http://www.shreveportastronomy.com || || ''✓''
|-
| Southern Maine Astronomers || Brunswick || Maine || 179 Neptune Drive,Suite 300 || http://www.southernmaineastronomers.org || || ''✓''
|-
| Penobscot Valley Stargazers || Stockton Springs || Maine || || http://www.gazers.org || || ''✓''
|-
| Howard Astronomical League of Central Maryland || Columbia || Maryland || 8630-M Guilford RdSuite 211 || http://www.howardastro.org || || ''✓''
|-
| Cumberland Astronomy Club || Frostburg || Maryland || || http://www.cumberlandastronomyclub.org || || ''✓''
|-
| TriState Astronomers || Hagerstown || Maryland || 823 Commonwealth Ave || https://www.tristateastronomers.org || || ''✓''
|-
| Westminster Astronomical Society || Westminster || Maryland || P.O. Box 1162 || http://www.westminsterastro.org || || ''✓''
|-
| South Shore Astronomical Society, The || Norwell || Massachusetts || 293 Pine Street || http://www.ssastros.org/testsite/index.html || || ''✓''
|-
| Oakland Astronomy Club || Auburn Hills || Michigan || P.O. Box 210554 || http://www.oaklandastronomy.net || || ''✓''
|-
| Kalamazoo Astronomical Society || Kalamazoo || Michigan || 600 West Vine Street, Suite 400 || http://www.kasonline.org/ || || ''✓''
|-
| Shoreline Amateur Astronomical Association || West Olive || Michigan || P.O. Box 201 || http://www.holland-saaa.org/ || https://www.facebook.com/ShorelineAstronomy || ''✓''
|-
| Minnesota Astronomical Society || Minneapolis || Minnesota || P.O. Box 14931 || http://www.mnastro.org || || ''✓''
|-
| Rochester Astronomy Club || Rochester || Minnesota || Box 513 || http://www.rochesterskies.org || || ''✓''
|-
| Jackson Astronomical Association || Jackson || Mississippi || P.O. Box 12586 || || https://www.facebook.com/groups/jacksonastro/ || ''✓''
|-
| Springfield Astronomical Society || Springfield || Missouri || || https://springfieldastronomy.org/ || || ''✓''
|-
| St. Louis Astronomical Society || St. Louis || Missouri || 13128 Cozyhill Drive || http://www.slasonline.org || || ''✓''
|-
| Astronomical Society of Eastern Missouri || Wentzville || Missouri || 206 Old Chesapeake Dr || https://www.asemonline.org/ || https://www.facebook.com/profile.php?id=100064380775869 || ''✓''
|-
| Yellowstone Valley Astronomy Association || Laurel || Montana || 759 Clarks River Rd || https://yvaamt.com/ || || ''✓''
|-
| Omaha Astronomical Society || Omaha || Nebraska || P.O. Box 34703 || https://www.omahaastro.com/ || || ''✓''
|-
| Keene Amateur Astronomers || Keene || New Hampshire || 94 Pako Avenue || http://www.keeneastronomy.org || || ''✓''
|-
| New Hampshire Astronomical Society || Manchester || New Hampshire || P.O. Box 5823 || http://www.nhastro.com || || ''✓''
|-
| Hopatcong Observatory Astronomy Club || Hopatcong || New Jersey || || https://www.hopatcongobservatory.org || || ''✓''
|-
| South Jersey Astronomy Club || Millville || New Jersey || || https://www.SJAC.us || || ''✓''
|-
| STAR Astronomy Society || Red Bank || New Jersey || P.O. Box 863 || https://www.starastronomy.org || || ''✓''
|-
| Astronomical Society of Toms River Area || Toms River || New Jersey || Ocean County College Building # 13, 1 College Drive || http://www.astra-nj.org || || ''✓''
|-
| Albuquerque Astronomical Society || Albuquerque || New Mexico || P.O. Box 50581 || https://www.taas.org || || ''✓''
|-
| Magdalena Astronomical Society || Magdalena || New Mexico || PO Box 125 || http://magdalenaastronomicalsociety.org/ || || ''✓''
|-
| Rio Rancho Astronomical Society || Rio Rancho || New Mexico || 609 Valley Meadows Dr. NE || http://www.rrastro.org || || ''✓''
|-
| El Valle Astronomers || Taos || New Mexico || 403 Valverde Commons Drive || https://elvalleastronomers.org/ || || ''✓''
|-
| Buffalo Astronomical Association || Buffalo || New York || || https://www.buffaloastronomy.com || || ''✓''
|-
| Mohawk Valley Astronomical Society || Clinton || New York || P.O. Box 52 || http://mvas-ny.org || || ''✓''
|-
| Astronomical Society of Long Island || Huntington || New York || 57 Conklin Lane || http://www.asliclub.org || || ''✓''
|-
| Amateur Observers' Society of New York || Mineola || New York || 425 Horton Highway || http://www.aosny.org || || ''✓''
|-
| Astronomy Section of the Rochester Academy of Science || Rochester || New York || P.O. Box 20292 || https://www.rochesterastronomy.org/ || || ''✓''
|-
| Custer Institute || Southold || New York || 1115 Main Bayview Rd.P. O. Box 1204 || http://www.custerobservatory.org/ || || ''✓''
|-
| Rockland Astronomy Club || Suffern || New York || 225 Route 59c/o Challenger Center || || || ''✓''
|-
| Astronomy Club of Asheville || Asheville || North Carolina || 75 St. Dunstan's Circle || http://www.astroasheville.org || || ''✓''
|-
| Cleveland County Astronomical Society || Boiling Springs || North Carolina || || http://www.ccastro.org || || ''✓''
|-
| Chapel Hill Astronomical and Observational Soc. || Chapel Hill || North Carolina || P.O. Box 3001 || https://chaosastro.org/ || || ''✓''
|-
| Raleigh Astronomy Club, Inc. || Raleigh || North Carolina || || https://raleighastro.org/ || || ''✓''
|-
| Cape Fear Astronomy Club || Wilmington || North Carolina || P.O. Box 7685 || http://www.capefearastro.org || || ''✓''
|-
| Miami Valley Astronomical Society || Beavercreek || Ohio || P.O. Box 340896 || http://www.mvas.org || || ''✓''
|-
| Richland Astronomical Society || Bellville || Ohio || P.O. Box 700 || http://www.wro.org || || ''✓''
|-
| Chagrin Valley Astronomical Society || Chagrin Falls || Ohio || 15735 Huntley RoadPO Box 11 || https://www.cvas.space/ || || ''✓''
|-
| Cincinnati Astronomical Society || Cleves || Ohio || 5274 Zion Rd || http://www.cinastro.org || || ''✓''
|-
| Millstream Astronomy Club || Findlay || Ohio || 2019 Sterling Court || || || ''✓''
|-
| Lima Astronomical Society || Lima || Ohio || P.O. Box 201 || https://limaastro com || || ''✓''
|-
| Toledo Astronomical Association || Sylvania || Ohio || 4815 New England Lane, Apt. 4 || http://toledoastronomy.org || || ''✓''
|-
| Stillwater Stargazers || || Ohio || || https://stillwaterstargazers.com/ || || ''✓''
|-
| Bartlesville Astronomical Society || Bartlesville || Oklahoma || P.O. Box 302 || https://sites.google.com/site/bartlesvilleastronomyclub/ || || ''✓''
|-
| Broken Arrow Sidewalk Astronomer || Broken Arrow || Oklahoma || 829 W. Vicksburg Street || || || ''✓''
|-
| Oklahoma City Astronomy Club || Oklahoma City || Oklahoma || P. O. Box 22804 || http://www.okcastroclub.com || || ''✓''
|-
| Odyssey Astronomy Club || Tribbey || Oklahoma || 30222 Slaughterville Rd. || || || ''✓''
|-
| Astronomy Club of Tulsa || Tulsa || Oklahoma || P. O. Box 470611 || http://www.astrotulsa.com || || ''✓''
|-
| Eugene Astronomical Society || Eugene || Oregon || P.O. box 50395 || http://www.eugeneastro.org || || ''✓''
|-
| Rose City Astronomers || Portland || Oregon || 1945 SE Water Ave || http://www.rosecityastronomers.org || || ''✓''
|-
| Umpqua Astronomers || Roseburg || Oregon || 604 Woodoak Drive || || || ''✓''
|-
| Southern Oregon Skywatchers || Talent || Oregon || 1557 Summer Place || https://www.orskywatchers.org/ || || ''✓''
|-
| Starlight Astronomy Club || Altoona || Pennsylvania || 702 Garden Street || http://www.starlightastronomyclub.org || || ''✓''
|-
| Bucks-Mont Astronomical Association || Ambler || Pennsylvania || 411 Susquehanna Rd || http://blog.bma2.org || || ''✓''
|-
| Chesmont Astronomical Society || Exton || Pennsylvania || PMB 218256 Eagleview Blvd || http://www.chesmontastro.org || || ''✓''
|-
| Amateur Astronomers Association of Pittsburgh || Glenshaw || Pennsylvania || P.O. Box 314 || http://www.3ap.org || || ''✓''
|-
| Delaware Valley Amateur Astronomers || Hatfield || Pennsylvania || 301 Logan Drive || http://www.dvaa.org || || ''✓''
|-
| Astronomy Enthusiasts of Lancaster County || Lititz || Pennsylvania || 325 Rudy Dam Road || http://www.aelc.us || || ''✓''
|-
| Oil Region Astronomical Society, Inc. || Oil City || Pennsylvania || P.O. Box 1535 || http://www.oras.org || || ''✓''
|-
| Central Pennsylvania Observers || State College || Pennsylvania || 345 Ridge Ave || http://www.cpoclub.org || || ''✓''
|-
| Chester County Astronomical Society || West Chester || Pennsylvania || 988 Meadowview Ln || http://www.ccas.us || || ''✓''
|-
| Astronomy Club of Augusta || Aiken || South Carolina || 1430 Morningside Drive || https://www.astroclubaugusta.weebly.com || || ''✓''
|-
| Lowcountry Stargazers || Charleston || South Carolina || P.O. Box 14453 || https://www.lowcountrystargazers.org || || ''✓''
|-
| Midlands Astronomy Club, Inc. || Columbia || South Carolina || P.O. Box 2527 || http://midlandsastronomyclub.org/ || || ''✓''
|-
| Grand Strand Astronomers || Conway || South Carolina || 1771 Alford Road || https://www.gsastro.org || || ''✓''
|-
| Barnard Astronomical Society || Chattanooga || Tennessee || || https://barnardastronomy.org/ || || ''✓''
|-
| Astronomy in the Parks Society || Hendersonville || Tennessee || 150 Roberta Dr || || || ''✓''
|-
| Bays Mountain Astronomy Club || Kingsport || Tennessee || Bays Mountain Park Association853 Bays Mountain Park Road || https://www.baysmountain.com/astronomy/astronomy-club/ || || ''✓''
|-
| Smoky Mountain Astronomical Society || Maryville || Tennessee || 3433 Ridgeway Trail || http://www.smokymtnastro.org/ || || ''✓''
|-
| Fort Worth Astronomical Society || Fort Worth || Texas || 5801 Trail Lake Drive || http://www.fortworthastro.com || || ''✓''
|-
| Hill Country Astronomers || Fredericksburg || Texas || P.O. Box 2043 || || || ''✓''
|-
| Psalm 19 Astronomy Society || Johnson City || Texas || 1216 Byrd Ranch Road || https://www.psalm19astronomy.org || || ''✓''
|-
| North Houston Astronomy Club || Kingwood || Texas || P.O. Box 5043 || http://www.astronomyclub.org/ || || ''✓''
|-
| South Plains Astronomy Club || Lubbock || Texas || 3521 50th StSpace 8 || http://southplainsastronomy.org || || ''✓''
|-
| West Texas Astronomers || Midland || Texas || P.O. Box 3284 || || || ''✓''
|-
| Texas Astronomical Society of Dallas || Richardson || Texas || P. O Box 830742 || http://www.texasastro.org || || ''✓''
|-
| Houston Astronomical Society || Spring || Texas || P.O. Box 131282 || http://www.astronomyhouston.org || || ''✓''
|-
| Salt Lake Astronomical Society || Tooele || Utah || 472 Country Club || https://www.slas.us || || ''✓''
|-
| Springfield Telescope Makers || Springtfield || Vermont || P. O. Box 601 || http://stellafane.org || || ''✓''
|-
| Charlottesville Astronomical Society || Charlottesville || Virginia || || http://www.cvilleastro.com || || ''✓''
|-
| Echo Ridge Astronomical Society || Elk Creek || Virginia || 766 Echo Ridge Lane || || || ''✓''
|-
| Rappahannock Astronomy Club || Fredericksburg || Virginia || P. O. Box 752 || http://www.raclub.org || || ''✓''
|-
| Shenandoah Astronomical Society || Front Royal || Virginia || 168 Hatcher Drive || || || ''✓''
|-
| Northern Virginia Astronomy Club || Oakton || Virginia || P.O. Box 3452 || http://www.novac.com || || ''✓''
|-
| Richmond Astronomical Society || Powhatan || Virginia || 1385 Quarter Mill Ct || http://www.richastro.org || || ''✓''
|-
| Blue Ridge Astronomy Club || Red House || Virginia || P.O. Box 70 || https://www.BlueRidgeAstro.com || || ''✓''
|-
| Back Bay Amateur Astronomers || Virginia Beach || Virginia || P.O. Box 9877 || http://www.backbayastro.org/ || || ''✓''
|-
| Battle Point Astronomical Association || Bainbridge Island || Washington || P. O. Box 10914 || http://www.bpastro.org || || ''✓''
|-
| Whatcom Association of Celestial Observers || Ferndale || Washington || P. O. Box 1721 || https://www.whatcomastronomy.com/ || || ''✓''
|-
| Friends of Galileo || Longview || Washington || 1632 22nd Ave || || || ''✓''
|-
| Everett Astronomical Society || Mill Creek || Washington || P.O. Box 13272 || http://everettastro.org/ || || ''✓''
|-
| Island County Astronomical Society || Oak Harbor || Washington || PO Box 325 || http://www.icas-wa.org/ || || ''✓''
|-
| Seattle Astronomical Society || Seattle || Washington || P. O. Box 31746 || http://www.seattleastro.org || || ''✓''
|-
| Olympic Astronomical Society || SIlverdale || Washington || 9689 Clipper Pl NW || http://www.olympicastronomicalsociety.org || || ''✓''
|-
| Spokane Astronomical Society || Spokane || Washington || P. O. Box 8114 || http://www.spokaneastronomical.org/ || || ''✓''
|-
| Yakima Valley Astronomical Society || Yakima || Washington || 505 Santa Roza Dr #B || https://www.yakimavalleyastro.org/ || || ''✓''
|-
| Central Appalachian Astronomy Club || Bridgeport || West Virginia || 324 Bartlett Ave || http://www.caacwv.com || || ''✓''
|-
| Kanawha Valley Astronomical Society || Charleston || West Virginia || P.O. Box 2132 || https://www.kvas.org || || ''✓''
|-
| Chippewa Valley Astronomical Society || Eau Claire || Wisconsin || PO Box 1713 || http://www.cvastro.org || || ''✓''
|-
| Wehr Astronomical Society || Franklin || Wisconsin || 9701 W College Ave || || || ''✓''
|-
| Northern Cross Science Foundation || Grafton || Wisconsin || 2292 Ridgewood Road || http://www.ncsf.info || || ''✓''
|-
| Sheboygan Astronomical Society, Inc. || Kohler || Wisconsin || P.O. Box 292 || http://www.shebastro.org/ || || ''✓''
|-
| Iowa County Astronomers || Lone Rock || Wisconsin || 1014 Fairview Court || http://www.icastro.org/ || || ''✓''
|-
| Madison Astronomical Society || Madison || Wisconsin || P.O. Box 5585 || https://madisonastro.org/ || || ''✓''
|-
| Milwaukee Astronomical Society || New Berlin || Wisconsin || || http://www.milwaukeeastro.org/ || || ''✓''
|-
| Northeast Wisconsin Stargazers || Sherwood || Wisconsin || P.O. Box 267 || https://www.new-star.org || || ''✓''
|}

===United Kingdom===

*[http://www.astronomyclubs.co.uk/Clubs/Counties.aspx UK Clubs] This link provides a list of clubs by county in the UK.

===Europe===

*[https://eas.unige.ch/affiliates.jsp European Clubs] This link provides a list of clubs in Europe.

===Austrailia===

*[https://astronomy.org.au/amateur/amateur-societies/australia/ Austrailian Clubs] This link provides a list of clubs in Austrailia.

===Canada===

*[https://www.skynews.ca/resources/astronomy-clubs/ Canadian Clubs] This link provides a list of clubs in Canada.

Telescope Basics

2025-01-28T19:22:40Z

Jmh921: Created page with "(This is a work in progress) An optical telescope is an instrument designed to gather and focus light. It does this through the use of lenses, mirrors, or a combination of t..."

(This is a work in progress)

An optical telescope is an instrument designed to gather and focus light. It does this through the use of lenses, mirrors, or a combination of the two. Other kinds of telescopes exist to gather energy from other parts of the electromagnetic spectrum, including infrared, ultraviolet, radio, microwave, x-ray, and gamma ray energy. However, this wiki is primarily concerned with light, so unless otherwise stated, our discussion will be about light.

Main Page

2025-01-28T19:18:49Z

Jmh921:

=Welcome to John's Astronomy and Astrophotography Wiki=

This wiki was created as a repository for information about amateur astronomy and astrophotography. Everyone is welcome to look around and make use of the information here.

Unfortunately, due to severe spam and cyber-vandalism issues, I was forced to disable editing ability for un-approved users. If you would like the ability to add or edit content, please e-mail me [mailto:JohnHaynes@jmhastronomy.com?Subject=AstroWiki%20Account%20Upgrade%20Request here]. As long as I know you're a real human being and actually want to contribute, I'd be happy to elevate your account.

I'd really like to have more contributors and get more utilization from this site. As such, I encourage people to share the site and help develop it further (with elevated credentials as mentioned above). The more people contributing, the better this site will be.

==Helpful Starting Points==

Here is a [[Main Topic Index]]

And here is a [[List of topics that probably need to be discussed]]

==More Info==
This Wiki works very much like the [https://en.wikipedia.org/wiki/Main_Page Wikipedia]. It is a collaborative effort. The Wikipedia didn't get to its current point of almost 7 million articles (in English alone, there's millions also in other languages) through the work of a single person. People contribute to a wiki because they have information or experience in a topic and a desire to share what they have.

I'd also like to add a couple people with higher-level access who can help improve the site. In particular, people with experience with PHP development and especially those with experience configuring and maintaining a Media Wiki site are welcome to contact me if they're interested in helping manage the site.

==Wiki Stuff==

This site uses MediaWiki, the same software used for the [https://en.wikipedia.org/wiki/Main_Page Wikipedia].

Consult the [https://www.mediawiki.org/wiki/Special:MyLanguage/Help:Contents User's Guide] for information on using the wiki software.

There are a lot of tutorials online for using MediaWiki. [https://www.mediawiki.org/wiki/Manual:FAQ#Basic_usage Here's a great start to the basics of creating and editing wiki pages].

==Some Additional Wiki Links==
* [https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:Configuration_settings Configuration settings list]
* [https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:FAQ MediaWiki FAQ]
* [https://lists.wikimedia.org/mailman/listinfo/mediawiki-announce MediaWiki release mailing list]
* [https://www.mediawiki.org/wiki/Special:MyLanguage/Localisation#Translation_resources Localize MediaWiki for your language]
* [https://www.mediawiki.org/wiki/Special:MyLanguage/Manual:Combating_spam Learn how to combat spam on your wiki]

Recommended Observing Sites

2024-08-12T17:17:16Z

Jmh921: Created page with "This page lists recommended locations for amateur astronomers to go for observing. Some sites will be specifically geared for observing (e.g. club dark sites), and others wil..."

This page lists recommended locations for amateur astronomers to go for observing. Some sites will be specifically geared for observing (e.g. club dark sites), and others will be areas typically away from or shielded from city lights and recommended by fellow amateur astronomers.

Please note: some clubs do not like to publish/advertise the locations of their dark sites (e.g. to avoid theft or vandalism), so please do not add locations such as that without permission of the club officers (simply link to the club's webpage and note that the location is confidential).

= North America =

== United States ==
=== New Hampshire ===

==== YFOS ====
Youngs Farm Observing Site - the official dark site of the [[New Hampshire Astronomical Society]].

This site is on private land leased to the club by the owners of a farm in rural New Hampshire. The site has a roll-of roof observatory with a C14 on a Losmandy Titan mount, a warming hut, a chemical toilet, and one or two Dobsonian telescopes for member use. The site is open for member use most of the year, but may be closed due to weather-related issues, particularly during mud season in the late winter/early spring.

The site's skies are approximately 3 or 4 on the [https://en.wikipedia.org/wiki/Bortle_scale Bortle scale].

The specific location is confidential and available to club members only.

More information and photographs are available on the [http://www.nhastro.com/observatory.php NHAS] website.

==== Joppa Hill Fields ====

A site in Bedford, NH approximately 20 minutes (11-ish miles) from Manchester, NH. This site is frequently used by members of the [[New Hampshire Astronomical Society]]. The area used for observing is the dirt parking lot adjacent to the athletic fields. There are no streetlights of concern, but there is occasionally traffic on Joppa Hill Rd (and drivers frequently are using their high beams). The site's [https://en.wikipedia.org/wiki/Bortle_scale Bortle] rating is between 4 and 5.

Google Map link: [https://maps.app.goo.gl/ZTjEZGxT7XWgAfUT7 Joppa Hill Fields]

=== Texas ===

==== HAS Dark Site ====

This is the official observing site of the [[Houston Astronomical Society]] and lies approximately 90 minutes (depending on traffic) west of downtown Houston, between Columbus and Weimar. The site has approximately 5 acres of cleared space surrounded by trees and well-away from city lights. The site's skies are approximately 3 or 4 on the [https://en.wikipedia.org/wiki/Bortle_scale Bortle scale].

The site's facilities include the main observatory building with 3 permanently-mounted telescopes and a climate-controlled chart room, two bunk houses (one designated for women and families), a restroom with showers, and a shed containing 2 Dobsonian telescopes for club member use. here are also 38 concrete pads for setting up observing equipment. Power outlets are available and all pads are within 50' of an outlet.

The society rents out spaces for members to keep trailers/campers/RVs at the site as well as 12' square plots east and west of the observatory building for members to construct private observatory buildings.

The exact location of the site is confidential and requires club membership and the completion of an orientation and quiz to obtain the location and combination to the gate (which changes annually). It is open to members and guests year-round, though occasionally inaccessible due to flooding on the roads nearby.

Three discoveries have been made at the site, including a comet, a supernova, and the first visual observation of a meteor impact on the moon.

=== Vermont ===

==== Stellafane/Breezy Hill ====
Situated approximately 3 1/2 miles west of the town of Springfield, Vermont is the site run by the [https://stellafane.org Springfield Telescope Makers] on Breezy Hill which is the location of the annual [https://stellafane.org/convention/index.html Stellafane] convention. The site's [https://en.wikipedia.org/wiki/Bortle_scale Bortle] rating is approximately 4.

Access to the site is available to members of the Springfield Telescope Makers club and to Stellafane convention participants (during the convention).

Google Map link: [https://www.google.com/maps/@43.2776441,-72.5139267,876m/data=!3m1!1e3?entry=ttu Stellafane]

== Canada ==

== Europe ==

== Asia ==

== Australia ==

== South America ==

== Africa ==

Recommended Vendors

2023-11-30T15:47:51Z

Jmh921: /* Storefronts */

This page is to provide a list of recommended vendors for telescopes and other astronomy and astrophotography equipment and software.

I (John) launched the page with some links to vendors in the United States. If you have helpful information, particularly about vendors outside of the US or specific to your geographic location, please feel free to add them to this page. Also feel free to expand on other entries to add details (e.g. this site's prices tend to be higher than average, but they have better service, etc...). This is a group effort, so the more we put in, the more helpful this tool is to us all.

=United States=

==Nationwide Online Retailers==

====[https://www.astronomics.com/ Astronomics]====

Astronomics is another reliable supplier of equipment. Located in Norman, OK, they have a wide range of equipment, from low-end to high-end.

Their in-house brand is Astro-Tech, which is mostly made by [[Guan Sheng Optical Co|GSO]].

Astronomics is the primary sponsor of the [https://www.cloudynights.com Cloudy Nights] website.

====[https://www.highpointscientific.com/ High Point Scientific]====

Another reliable supplier of telescopes and astronomy equipment, based in Montague, NJ

Their in-house brand is Apertura, yet again made by [[Guan Sheng Optical Co|GSO]].

====[https://www.milehighastro.com/ Mile High Astronomy]====

Another reliable supplier of telescopes and astronomy equipment, based in Lakewood, CO, just outside of Denver. MHA ships nationwide by UPS.

====[https://optcorp.com/ Oceanside Photo and Telescope (OPT)]====

OPT has one of the largest selections online in the United States. Previously based in Oceanside, CA, they have recently moved to nearby Carlsbad. Their equipment ranges from low-end beginner stuff to some of the highest-end equipment available. They also have fairly knowledgeable staff. They are a reliable supplier of amateur astronomy equipment, if not the cheapest.

Their in-house brand is Third Planet Optics or TPO (which is, of course, OPT backwards). Most of the TPO stuff is made by [[Guan Sheng Optical Co|GSO]].

====[https://www.telescope.com/ Orion Telescopes & Binoculars]====

Orion is one of the top two vendors of telescopes; the other being Celestron. Orion's equipment is primarily made by Synta in mainland China; Celestron and SkyWatcher gear is made in the same factory. The quality of Orion's equipment is just as good as any of the other mass retailers (Celestron, SkyWatcher, Meade), which is quite high - - because it's all made in the same factory, and then painted different colors for the different vendors. And they have very good customer service as well.

However there are two big negative marks against Orion. One is that much Orion-branded astrogear is priced higher than equivalent equipment labelled with different brand names. There are a number of examples of this, including telescopes, eyepieces, and mounts.

A second is that Orion will not service or provide any support whatsoever to third-parties. To Orion, a third-party is anyone who hasn't bought Orion equipment from Orion itself, or an authorized dealer. In other words, if you buy used Orion gear from a fellow amateur astronomer, Orion will not lift a finger to help you with this gear in the slightest - if you need a part, if you need information. Nothing. It is the only major vendor that has this policy.

====[http://scopestuff.com/ ScopeStuff]====

This is a small web-based outfit selling lots of parts and accessories. One of their specialties is mounting hardware, including dovetail plates and tube rings as well as piggyback mounting hardware. They have great customer service and maintain their own database of details on a wide variety of scopes and what is needed for mounting them. If you don't now what you need, contact them and they can usually figure it out for you.

====[https://www.astronomy-mall.com/astro.parts.outlet/ Telescope Parts Outlet]====

This guy has a wide variety of used scopes and parts. He has a huge list of items available, and a lot of stuff isn't on the list. If you're missing a part or need a repair part, he's a great source, particularly for Orion, Celestron, and Meade.

====[https://smile.amazon.com/ref=smi_se_dshb_bk_smi Amazon.com]====

While Amazon does carry a large number of telescopes from various brands, caution is strongly recommended when purchasing via Amazon.

First, a lot of the products sold on Amazon are sold by other vendors through the Amazon interface. These vendors are known as resellers - they typically buy astronomical equipment from a reputable seller (listed here), and then sell it to you. While Amazon regulates this to some extent, if you're not buying FROM Amazon themselves, you may run into trouble with shipping and fulfillment as well as quality. Some buyers have reported issues with incomplete items (e.g. buying a Dob and either only getting the tube and not getting the base or only getting the base and not the tube). Others have had items damaged or lost in shipping. While Amazon typically works to make things right, often by refunding the purchase, this can be a serious hassle.

Second, most of the stuff carried on Amazon is lower-end equipment targeted at a poorly-educated retail market. In other words: lots of "department-store telescopes." A good example here is the Celestron PowerSeeker line (which is nearly entirely poor quality) is promoted and shows up prominently in search results.

Third, if you buy from a reseller, you have no warranty protection whatsoever. The vendors (Celestron, Orion, TeleVue, etc.) will not honor your purchase from a reseller. Therefore, you will have no recourse if there's anything wrong with your scope.

Lastly, the reviews on Amazon are often a very poor indicator. This is due to widespread abuse of the review system and outright fraudulent entries to boost search result positioning. This leads to lousy telescopes like the PowerSeeker 127eq receiving very high ratings and, with them, a prominent position in search results.

These problems, along with the lack of informed support from the vendor (most good vendors have informed and reasonably knowledgeable staff that can answer questions), make Amazon a very questionable source. This isn't to say you can't get decent equipment off Amazon, but that you should be extra-careful before ordering from them.

==Storefronts==

===California===

====Watsonville====

[https://www.telescope.com/content.jsp?pageName=StoreInformation&src=footer2 Orion Telescopes & Binoculars]

89 Hangar Way Watsonville, CA 95076, (831) 763-7000

====Cupertino====

[https://www.telescope.com/content.jsp?pageName=StoreInformation&src=footer2 Orion Telescopes & Binoculars]

10555 S. De Anza Blvd. Cupertino, CA 95014, (408) 255-8770

===Colorado===

====Denver====

[https://www.milehighastro.com Mile High Astronomy]

9797 West Colfax Avenue #3vv, Lakewood, CO, 80215, 877-279-5280

===Texas===

====Houston====

[https://www.landseaskyco.com Land Sea and Sky and Texas Nautical Repair]

1925A Richmond Ave. Houston, TX 77098, 713-364-0260

====San Antonio====

[https://www.analyticalsci.com/ Analytical Scientific]

11049 Bandera Road
San Antonio, TX 78250
210-684-7373

=Canada=

====[https://khanscope.com/ Khan Scope Center]====

====[https://www.ontariotelescope.com/ Ontario Telescopes]====

====[https://www.kwtelescope.com/ KW Telescope]====

====[https://www.all-startelescope.com/ All Star Telescope]====

====[https://focusscientific.com/ Focus Scientific]====

=European Union=

====[https://www.astroshop.eu/ Astroshop]====

A German online telescope and other optical instrument retailer, also operates a storefront in Landsberg am Lech, Germany. Ships anywhere in Europe, and to most of the world, where commercial parcel deliveries are available.

Has an in-house brand Omegon, mostly sources optics from GSO and Synta.

====[https://www.teleskop-express.de/shop/index.php/language/en Teleskop-Express]====

Another well-known German online telescope and other optical instrument retailer, located in Ebersberg, Germany. Will happily ship to pretty much anywhere in the world, for a reasonable price.

Has an in-house brand Teleskop-Service, or just TS.

=United Kingdom=

====[https://www.firstlightoptics.com/ First Light Optics]====

Probably the largest UK-based optical instrument retailer, but also will happily ship anywhere in the EU and to most of the world, operating from Exeter, Devon, UK.

====[https://www.orionoptics.co.uk/home.html Orion Optics UK]====

Not to be confused with the Orion Telescopes & Binoculars of the USA side of the world. This manufacturer and retailer mostly sells their own branded instruments, but also carries stock of other popular brands.

=Australia=

=India=

=Japan=

=South America=

Star Parties, Festivals, and Meetings

2023-04-22T19:10:23Z

Jmh921:

The following is a list of Star Parties and similar events
(Updated 4/22/2023)

=United States=
{| class="wikitable"
|-
! Party Name
! Starts
! Ends
! Location
! State
! Link
! Notes
|-
| Green Bank Star Quest
| 6/21/2023
| 6/24/2023
| Green Bank
| WV
| https://greenbankstarquest.org/
|
|-
| Almost Heaven Star Party
| 8/18/2023
| 8/22/2023
| Circleville
| WV
| https://www.ahsp.org/
|
|-
| Bootleg Spring Star Party
| 5/18/2023
| 5/21/2023
| Harmon
| IL
| http://bootlegastronomy.com/
|
|-
| Bootleg Fall Star Party
| 9/14/2023
| 9/17/2023
| Harmon
| IL
| http://bootlegastronomy.com/
|
|-
| Great Lakes Star Gaze
| 9/14/2023
| 9/17/2023
| Gladwin
| MI
| http://www.greatlakesstargaze.com/
|
|-
| Rocky Mountain Star Stare
| 6/14/2023
| 6/18/2023
| Gardner
| CO
| https://rmss.org/
|
|-
| Bryce Canyon Astronomy Festival
| 6/14/2023
| 6/17/2023
| Bryce Canyon Park
| UT
| https://www.brycecanyoncountry.com/events/bryce-canyon-astronomy-festival-2/
|
|-
| Idaho Star Party
| 9/15/2023
| 9/17/2023
| Bruneau Dunes Park
| ID
| https://boiseastro.org/event-4996997
|
|-
| Black Canyon Astronomy Festival
| 9/22/2023
| 9/24/2023
| Montrose
| CO
| https://www.nps.gov/blca/planyourvisit/astrofest.htm
|
|-
| Cherry Springs Star Party
| 6/15/2023
| 6/18/2023
| Coudersport
| PA
| https://sites.google.com/astrohbg.org/Cherry-Springs-Star-Party
|
|-
| Stellafane
| 8/17/2023
| 8/20/2023
| Springfield
| VT
| https://stellafane.org/
|
|-
| Acadia Night Sky Festival
| 9/21/2023
| 9/25/2023
| Bar Harbor
| ME
| https://www.acadianightskyfestival.org/
|
|-
| Stars Over Katahdin
| TBA
| TBA
| Millinocket
| ME
| https://www.friendsofkww.org/stars/
|
|-
| Astrophotography Conference
| 10/12/2023
| 10/15/2023
| Tupper Lake
| NY
| https://www.adirondackskycenter.org/events/Astrophotography-Conference-2023
|
|-
| Black Forest Star Party
| 9/15/2023
| 9/17/2023
| Potter County
| PA
| https://bfsp.org/
|
|-
| Oregon Star Party
| 7/18/2023
| 7/23/2023
| Prineville
| OR
| https://oregonstarparty.org/
|
|-
| Table Mountain Star Party
| 8/8/2023
| 8/12/2023
| Oroville
| WA
| http://www.tmspa.com/
|
|-
| Nebraska Star Party
| 7/16/2023
| 7/22/2023
| Valentine
| NE
| https://www.nebraskastarparty.org/
|
|-
| Okie-Tex Star Party
| 9/8/2023
| 9/16/2023
| Kenton
| OK
| http://www.okie-tex.com/
|
|-
| Dakota Nights Festival
| TBA
| TBA
| Medora
| ND
| https://www.nps.gov/thro/learn/nature/dakota-nights-festival.htm
|
|-
| Badlands Festival
| 7/14/2023
| 7/16/2023
| Rapid City
| SD
| https://www.nps.gov/thingstodo/badl-astronomy-festival.htm
|
|-
| Midsouth Stargaze
| 4/19/2023
| 4/22/2023
| French Camp
| MS
| https://rainwaterobservatory.org/events
|
|-
| Texas Star Party
| 5/14/2023
| 5/21/2023
| Fort Davis
| TX
| https://texasstarparty.org/
|
|-
| Orange Blossom Special
| 2/7/2024
| 2/11/2024
| Dade City
| FL
| https://www.stpeteastronomyclub.org/OBS/
|
|-
| Winter Star Party
| 2/5/2024
| 2/11/2024
| Scout Key
| FL
| https://www.scas.org/winter-star-party/
|
|-
| Death Valley Dark Sky Festival
| 2/10/2023
| 2/12/2023
| Death Valley
| CA
| https://www.nps.gov/deva/planyourvisit/death-valley-dark-sky-festival.htm
|
|-
| California Dark Sky Festival
| 10/12/2023
| 10/15/2023
| Panamint Valley
| CA
| https://www.easternsierraobservatory.com/california-dark-sky-festival
|
|-
| Grand Canyon Star Party
| 6/10/2023
| 6/17/2023
| Grand Canyon Park
| AZ
| https://www.nps.gov/grca/planyourvisit/grand-canyon-star-party.htm
|
|-
| Golden State Star Party
| 6/14/2023
| 6/18/2023
| Bieber
| CA
| http://goldenstatestarparty.org/
|
|-
| Advanced Imaging Conference
| TBA
| TBA
| San Jose
| CA
| https://www.advancedimagingconference.com/
|
|-
| Night Sky Festival
| 10/13/2023
| 10/14/2023
| Twentynine Palms
| CA
| https://www.skysthelimit29.org/night-sky-festival.html
|
|}

Star Parties, Festivals, and Meetings

2023-04-22T19:05:47Z

Jmh921: Created page with "The following is a list of Star Parties and similar events in the United States (Updated 4/22/2023) {| class="wikitable" |- ! Party Name ! Starts ! Ends ! Location !..."

The following is a list of Star Parties and similar events in the United States

(Updated 4/22/2023)

{| class="wikitable"
|-
! Party Name
! Starts
! Ends
! Location
! State
! Region
! Link
! Notes
|-
| Green Bank Star Quest
| 6/21/2023
| 6/24/2023
| Green Bank
| WV
| East
| https://greenbankstarquest.org/
|
|-
| Almost Heaven Star Party
| 8/18/2023
| 8/22/2023
| Circleville
| WV
| East
| https://www.ahsp.org/
|
|-
| Bootleg Spring Star Party
| 5/18/2023
| 5/21/2023
| Harmon
| IL
| Midwest
| http://bootlegastronomy.com/
|
|-
| Bootleg Fall Star Party
| 9/14/2023
| 9/17/2023
| Harmon
| IL
| Midwest
| http://bootlegastronomy.com/
|
|-
| Great Lakes Star Gaze
| 9/14/2023
| 9/17/2023
| Gladwin
| MI
| Midwest
| http://www.greatlakesstargaze.com/
|
|-
| Rocky Mountain Star Stare
| 6/14/2023
| 6/18/2023
| Gardner
| CO
| Mountains
| https://rmss.org/
|
|-
| Bryce Canyon Astronomy Festival
| 6/14/2023
| 6/17/2023
| Bryce Canyon Park
| UT
| Mountains
| https://www.brycecanyoncountry.com/events/bryce-canyon-astronomy-festival-2/
|
|-
| Idaho Star Party
| 9/15/2023
| 9/17/2023
| Bruneau Dunes Park
| ID
| Mountains
| https://boiseastro.org/event-4996997
|
|-
| Black Canyon Astronomy Festival
| 9/22/2023
| 9/24/2023
| Montrose
| CO
| Mountains
| https://www.nps.gov/blca/planyourvisit/astrofest.htm
|
|-
| Cherry Springs Star Party
| 6/15/2023
| 6/18/2023
| Coudersport
| PA
| Northeast
| https://sites.google.com/astrohbg.org/Cherry-Springs-Star-Party
|
|-
| Stellafane
| 8/17/2023
| 8/20/2023
| Springfield
| VT
| Northeast
| https://stellafane.org/
|
|-
| Acadia Night Sky Festival
| 9/21/2023
| 9/25/2023
| Bar Harbor
| ME
| Northeast
| https://www.acadianightskyfestival.org/
|
|-
| Stars Over Katahdin
| TBA
| TBA
| Millinocket
| ME
| Northeast
| https://www.friendsofkww.org/stars/
|
|-
| Astrophotography Conference
| 10/12/2023
| 10/15/2023
| Tupper Lake
| NY
| Northeast
| https://www.adirondackskycenter.org/events/Astrophotography-Conference-2023
|
|-
| Black Forest Star Party
| 9/15/2023
| 9/17/2023
| Potter County
| PA
| Northeast
| https://bfsp.org/
|
|-
| Oregon Star Party
| 7/18/2023
| 7/23/2023
| Prineville
| OR
| Northwest
| https://oregonstarparty.org/
|
|-
| Table Mountain Star Party
| 8/8/2023
| 8/12/2023
| Oroville
| WA
| Northwest
| http://www.tmspa.com/
|
|-
| Nebraska Star Party
| 7/16/2023
| 7/22/2023
| Valentine
| NE
| Plains
| https://www.nebraskastarparty.org/
|
|-
| Okie-Tex Star Party
| 9/8/2023
| 9/16/2023
| Kenton
| OK
| Plains
| http://www.okie-tex.com/
|
|-
| Dakota Nights Festival
| TBA
| TBA
| Medora
| ND
| Plains
| https://www.nps.gov/thro/learn/nature/dakota-nights-festival.htm
|
|-
| Badlands Festival
| 7/14/2023
| 7/16/2023
| Rapid City
| SD
| Plains
| https://www.nps.gov/thingstodo/badl-astronomy-festival.htm
|
|-
| Midsouth Stargaze
| 4/19/2023
| 4/22/2023
| French Camp
| MS
| South
| https://rainwaterobservatory.org/events
|
|-
| Texas Star Party
| 5/14/2023
| 5/21/2023
| Fort Davis
| TX
| South
| https://texasstarparty.org/
|
|-
| Orange Blossom Special
| 2/7/2024
| 2/11/2024
| Dade City
| FL
| Southeast
| https://www.stpeteastronomyclub.org/OBS/
|
|-
| Winter Star Party
| 2/5/2024
| 2/11/2024
| Scout Key
| FL
| Southeast
| https://www.scas.org/winter-star-party/
|
|-
| Death Valley Dark Sky Festival
| 2/10/2023
| 2/12/2023
| Death Valley
| CA
| Southwest
| https://www.nps.gov/deva/planyourvisit/death-valley-dark-sky-festival.htm
|
|-
| California Dark Sky Festival
| 10/12/2023
| 10/15/2023
| Panamint Valley
| CA
| Southwest
| https://www.easternsierraobservatory.com/california-dark-sky-festival
|
|-
| Grand Canyon Star Party
| 6/10/2023
| 6/17/2023
| Grand Canyon Park
| AZ
| Southwest
| https://www.nps.gov/grca/planyourvisit/grand-canyon-star-party.htm
|
|-
| Golden State Star Party
| 6/14/2023
| 6/18/2023
| Bieber
| CA
| Southwest
| http://goldenstatestarparty.org/
|
|-
| Advanced Imaging Conference
| TBA
| TBA
| San Jose
| CA
| Southwest
| https://www.advancedimagingconference.com/
|
|-
| Night Sky Festival
| 10/13/2023
| 10/14/2023
| Twentynine Palms
| CA
| Southwest
| https://www.skysthelimit29.org/night-sky-festival.html
|
|}

Chromatic aberration

2022-05-26T01:05:07Z

Jmh921:

Chromatic Aberration is an optical aberration that occurs when light passes through a medium such as a glass lens which causes different wavelengths (colors) of light to focus at different focal lengths and degrades the image.

''this page is a work in progress''

==Refraction==

Refraction is the bending of light by passing it through a medium. While the speed of light in a vacuum is approximately 300,000 kilometers per second, when light passes through a medium such as air, water, or glass, it is slowed. Different wavelengths of light, which are perceived by human eyes as colors, are affected to differing amounts. Light with shorter wavelengths, which appears bluer, is bent to a greater degree than is light with a longer, redder, wavelength.

[[File:Light dispersion conceptual waves.gif|thumb|Light passing through a typical prism.]]

The same phenomenon is what makes a prism split white light into separate colors also causes chromatic aberration. In the example image to the right, as white light passes through the glass prism, the various colors of light are slowed at varying rates, causing them to bend, or refract.

In a typical glass [[convex]] lens, the glass is thicker in the center and thinner along the edges of the lens. When light passes through the glass, it is slowed down. Because there is less glass on the edges, that light is slowed less than the light closer to the center. This causes the path of all wavelengths of light to bent toward the center axis of the lens. Where the light rays all converge is the focal point.

But because red light is less affected than blue light, the focal point for red light will be further from the lens than it will be for blue light as shown here:

[[File:Chromatic aberration lens diagram.svg|Chromatic aberration lens diagram]]

The visible result is that objects in the view tend to be blurred somewhat. This is most easily noticeable in images of objects with distinct edges, particularly if there is also a significant contrast between colors or light and dark areas of the image.

[[File:Chromatic aberration (comparison).jpg|thumb|Above: an image without chromatic aberration, below the same image with chromatic aberration apparent.]]

Telescopes which use mirrors instead of lenses to gather and focus light are not subject to chromatic aberration as the light does not pass through glass. When an eyepiece is used, there may be some chromatic aberration caused by the eyepiece, though this is typically less noticeable.

The problem is exacerbated by the thickness of the glass the light is passing through. Lenses with a shorter [[focal ratio]] have a more distinct curvature to them, while longer focal ratios have less significant curvature. This means that in lenses with shorter focal ratios, the difference between the center of the lens and the edges is much greater than that of shorter focal ratio lenses. As such, the amount of slowing of the light is more varied in a shorter focal length lens, which increases the effect of chromatic aberration. For this reason, most simple single-lens refractors tend to have long focal ratios to reduce the appearance of chromatic aberration.

==Reducing Chromatic Aberration==

A mentioned previously, longer focal ratios reduce the appearance of the aberration, bringing the various focal points of different wavelengths of light closer together. This was the earliest way of dealing with the problem.

The problem chiefly applies to [[Refractor|refracting telescopes]]. In

==References==
<references group=""/>