Jerry, Thanks for the information. I have been doing a little searching around on the astrometry subject for the last few days. Of the four plate solving programs you mentioned (AIP4WIN, MaximDL, MPO Canopus, Astrometrica) seems I have 3 of them...hehe. I haven’t actually fired up Astrometrica yet, though I have it down loaded. It has a 100 day free trial after which if you like it, it costs only about 25L or $33.00 to buy it. I am deciding on a catalog before I fire it up. The USNO-A2.0 has 526,000,000 measured star locations in it which they claim would include 12,000 stars per square degree. The small version USNO-SA2.0 had 57,000,000 measured star positions which would include about 1300 stars per square degree. The small one would be very adequate for my purposes. I perused the Maxim DL manual for astrometry and the subject is covered in there but it is broken up into different locations in the book and no tutorial like they do with some subjects. Maxim will probably be the software I use for astrometry once I figure out what to do; unless I really like Astrometrica. I do have the version of Maxim with PinPoint in it so I should be OK there. AIP4WIN had the best presentation on doing astrometry. I went through their tutorial and found it fun and fairly easy. It seems that my equipment (Canon XT and Orion 100mm ED) are at the lower fringes of what is needed to do good science. I think I will try starting out imaging asteroids like Ceres, Vesta, Pallas and the “big boys”, do the astrometry, and work my way down in size from there. It sounds like a lot of fun to me. I ran across an article that shows how to do astrometry with a video camera. They claim that In considering the relative sources of error between using a CCD camera and a video camera, it may be expected that the enhanced timing precision associated with a video camera will lead to it being the preferred astrometric tool if the motion of an asteroid is greater than about 100(arc-seconds)/minute. For example, nine astrometric positions reported on MPEC 2009-F01 http://www.cfa.harvard.edu/mpec/K09/K09F01.html were measured from images derived from video; those positions have an RMS residual of less than 0.3². Like so many things in astronomy there are a plethora of ways of doing things that the beginner can quickly get swamped. I am going to stick with what I have and see what I can learn. Jim
participants (1)
-
Jim Gibson