spectro-aras.com

Hello,


one of the challenge in slit based spectroscopy is to find your target. Because the guiding camera have usually a small field of view, finding your target can be combersome. Well, it's easier in imaging with a 24mm or larger chip size!

Here is a solution which I used at OHP spectroscopy workshop and that worked very well. To be honnest, I didn't have a finderscope on my refractor and I was a little bit lazy in my polar alignment...

The trick is:
-capture a long exposure with your guiding camera & save as a FITS file
-go to Astrometry.net: http://nova.astrometry.net/
-upload your FITS file
-in few seconds/minutes, the web site gives you your image coordinates so you can resynch your scope and then point to your target!

Below are few screen shots with an actual exemple (not very good, slit visible, few stars) - and it worked!


So if you are lost and do not know where you scope is pointing at in the sky, try this, it can help saving some time...


Cordialement,
Olivier Thizy
Vous ne verrez plus des étoiles comme avant !
http://www.shelyak.com/en/

It's worth noting that astrometry.net is free and open source, and can be run locally on a UNIX machine. According to their documentation it is also reported to run on Cygwin. Useful for field operation.

http://astrometry.net/use.html

The data files are quite large, but you can just download the set suitable for your guider plate scale. Works really well for me on Linux.

Malc