Mach2 and Horizons

Terri Zittritsch

Last night I was able to image for 6 hours or so, including some imaging of  Atlas C/2019 Y4.    I used the opportunity to try out the Horizons software, so I downloaded the ephemeris data for Atlas.   I did a careful polar alignment, and after imaging a few targets, horizons put Atlas in the very middle of my imaging window, and it worked perfectly.     It tracked Atlas and kept it in the middle of my screen and on longer exposures of a minute or more I could see the stars start to elongate.    For image processing, I'm not entirely sure if it's easier tracking on the comet or guiding on a star.   After marveling on how well the comet was being tracked and stayed in the middle of my imaging screen, I decided for imaging that I'd guide on a star and do the post processing in this way, especially since I had a mono-camera on the scope.  I don't actually know if it makes a difference or not, but know I have a bit of processing to do based on past experience.   I really should have put a color camera on for this.. as I know I'm going to have a lot of processing to do!

Also, not sure if this is just normal for an A-P mount to have this kind of repeatability and precision, or if this is attributed to the mach2 with encoders.   After my very first plate solve, subsequent solves seem to go very fast.    Very confidence inspiring, even with terrible seeing.