using the stars option in view
using the stars option in view
Went through the tutorial #9 on astrometry and photometry with flying colors. I then tried to do the same using one of my DSO images. I cannot select any stars (no rectangle shows up around any star). I do not know why this happening so I tried to attach one of my fit files that had the problem but I received file too big to be attached (30,150 KB). I also played around with the star options in preferences but nothing seemed to make any difference. Finally, I submitted the image to nova astronomy.net and they were able to plate solve it with no problems. Any questions or help that would aid me in resolving this issue would be appreciated.
Re: using the stars option in view
Maybe the stars where extremely oversampled and saturated? In this case astrometry on those stars will not be precise in any case. By the way you can force the collection of those star with CTRL + click. Then proceed with the command Astrometry as usual, but be very careful with the O-Cs, if they become too large then those stars cannot be used for measuring minor planets.
Instead, you will have to manually select 10-15 good stars and use the "manual reference" astrometry with a good catalog.
All that is for precise astrometry. If instead you simply needed to plate solve the image as a test, just use the online service, but the precision may not be enough.
If instead you just need to find out the coordinates of the center of the image, and AA refuses to work with such saturated stars, use this trick: command Image/Binning/"Pixel 2x2" (or more) then plate solve in AA.
Instead, you will have to manually select 10-15 good stars and use the "manual reference" astrometry with a good catalog.
All that is for precise astrometry. If instead you simply needed to plate solve the image as a test, just use the online service, but the precision may not be enough.
If instead you just need to find out the coordinates of the center of the image, and AA refuses to work with such saturated stars, use this trick: command Image/Binning/"Pixel 2x2" (or more) then plate solve in AA.
Re: using the stars option in view
Thanks, control - click did the trick. Looked at the image I was using with the 3D option and most of the stars were flat topped (saturated). Unfortunately have a bad habit of making pretty pictures of my DSOs which in many cases produces saturated stars. Completed a Astro7 astrometry & photometry run on the image and compared it with the Nova Astronomy.net plate solve results. Answers in Astro7 statistics were the same as the Nova result.
