Star Collimation

[Neillo]

Hi everyone, 

Apologies for the Newb question, i am new to the hobby and i am trying to collimate my new Celestron Astromaster 130EQ. It came nowhere near in collimation out of the factory, which was rather annoying.

I have been learning about star collimation, i was wondering if anyone has any experience using Jupiter to collimate as opposed to a star, as Jupiter is quite visible at the moment where i live.

Any help is appreciated!

Edited January 25 by Neillo

[Mr Spock]

Hi, no, you need a star. You need to be able to see the airy disc and diffraction rings when focussed; then when defocussed you will get the correct image. You won't get that with Jupiter.

 

[Kon]

You can collimate on Jupiter's moons but it is a lot trickier as you need to be able to get an airy disc around it; it requires a planetary camera and the program Metaguide. Similar principle to star collimation as you are looking at the airy disc around. As Michael said, you are better off with a star as you can do it with an eyepiece.

Edited January 25 by Kon

[Peter Drew]

You can collimate using Jupiter.  If you slightly defocus you will see a ghost annulus of Jupiter and depending how concentric that annulus is will be a measure of your collimation quality.  It has the advantage of not twinkling like a sar does so helpful during poor seeing.  In good seeing a star is more accurate.     🙂

[Spile]

One thing to bear in mind is that as well as using a star you will need to use high magnification.   I centre (this is important) Polaris in the eyepiece using high (200X) power. I move the focuser slightly in and then out and compare both views. The out of focus views show unbroken, concentric rings.

Edited January 25 by Spile

[AstroMuni]

On 25/01/2024 at 09:25, Neillo said:

am trying to collimate my new Celestron Astromaster 130EQ

Collimating with a cheshire can be tricky as the focuser tube is quite wobbly on that scope. But thats the way you would need to start. Once you have got a decent collimation you could try and improve this by collimating with a star. When collimating with stars, you would need to get higher power eyepieces than the std ones supplied, so that you can easily see the airy disk.

Edited January 31 by AstroMuni

[Spile]

I would recommend checking the alignment of a primary mirror with a cap.