Does my AstroMaster 130 have a spherical or parabolic mirror? What is th...

The AstroMaster 130 has a spherical mirror. Telescope mirrors are described by their figures in terms of the curvature of the optical surface. A spherical figure is one type of...

Does my AstroMaster 130 have a spherical or parabolic mirror? What is th...

The AstroMaster 130 has a spherical mirror. Telescope mirrors are described by their figures in terms of the curvature of the optical surface. A spherical figure is one type of...

What is the size of the threading holding the visual back to my Schmidt-...

The baffle lock nut is the back end of the C8 and C9.25; it is a 2 in x 24 thread.On the C11 and C14 (and the EdgeHD 9.25), there...

What is the size of the threading holding the visual back to my Schmidt-...

The baffle lock nut is the back end of the C8 and C9.25; it is a 2 in x 24 thread.On the C11 and C14 (and the EdgeHD 9.25), there...

What is the threading on the outside of my Celestron GoTo mount’s power ...

Many of Celestron’s GoTo mounts use the same power jack. These jacks are threaded on the outside. The threading is M8x0.75.On the CGEM, CGEM DX and the CGE Pro, power...

What is the threading on the outside of my Celestron GoTo mount’s power ...

Many of Celestron’s GoTo mounts use the same power jack. These jacks are threaded on the outside. The threading is M8x0.75.On the CGEM, CGEM DX and the CGE Pro, power...

How can I make my own collimating tool to use with my Newtonian reflector?

There are several ways to do-it-yourself when it comes to collimating tools. The easiest way is to drill a 1/16” to 1/8” hole in the center of your eyepiece drawtube...

How can I make my own collimating tool to use with my Newtonian reflector?

There are several ways to do-it-yourself when it comes to collimating tools. The easiest way is to drill a 1/16” to 1/8” hole in the center of your eyepiece drawtube...

Why can’t I find the moon and planets with my SkyProdigy?

If your SkyProdigy can locate deep-sky objects but can’t find the moon and planets, check your mount’s real-time clock (RTC). The RTC keeps Universal Time (UT), widely used by astronomers....

Why can’t I find the moon and planets with my SkyProdigy?

If your SkyProdigy can locate deep-sky objects but can’t find the moon and planets, check your mount’s real-time clock (RTC). The RTC keeps Universal Time (UT), widely used by astronomers....

What is Periodic Error (PE)? And how do I correct it?

Periodic error (PE) is the name for the inevitable small mechanical errors that occur in the drive gearing as the scope is tracking during long-exposure imaging. Since these errors are...

What is Periodic Error (PE)? And how do I correct it?

Periodic error (PE) is the name for the inevitable small mechanical errors that occur in the drive gearing as the scope is tracking during long-exposure imaging. Since these errors are...