![]() When I tested ASIAIR's plate solve to estimate the center of my simulator's display, I usually came up with no more than a few arc seconds of error. It is probably just simply the case that ASIAIR is solving for the position your telescope is pointed to tonight, while is solving for the position of stars as if it were January 2000 AD.įor what its worth, I had used the Hipparcos catalog (HYG 3.0) in my mount simulator ( ), which gives star coordinates referenced to J2000.0, and I had used nutation and precession (precession has quite a bit less delta than nutation, by the way) to convert J2000.0 to JNOW, so that the simulator displays what we see in the sky right now. Please join or request to join the group, and then youll be able to post a new topic. Hi guys, I sent in astrometry for (3122) Florence the other night, Id had to wait two weeks for a second lot of observations due to weather. ![]() Only group members can post in a groups forum. You could have copied the files as well using sudo instead of changing the access permissions. The difference between J2000.0 and JNOW appears to be consistent with the numbers you have obtained, so there is likely no error in plate solving by ASIAIR (at least not to the magnitude that you saw). job: 5771145 RA center: 16 h 26 m 49 s.2. /usr/share/astrometry is a system directory and therefore by default only can be written to by the root user. Anecdotal evidence for usage of astronomy forums and sites again suggests a ratio of. I think I have also seen ZWO folks confirm that the ASIAIR uses JNOW.Ī uses J2000.0 according to this: Diversifying the future: opening astronomy and geophysics to all. Run this to open a command box that can run solve-field. Otherwise when we execute a GOTO in ASIAIR, we won't land on the correct spot. In the Local Solver folder that was installed in Programs Files (x86), there should be a Cygwin.bat file. (Another source of error could be how atmospheric refraction is estimated - not knowing your latitude and observing time, I can't venture to guess if that is an additional source of error).įrom the RA and DEC of stars in its database, we know that ASIAIR must use JNOW, since that is where the objects are when you are trying to point to them tonight, and not in January 2000 AD. These are expected to be filled in during the coming months. Approximately 4.9 square degrees (0.016 of the survey area) has sources that are missing due to various issues in the database population procedures. Your numbers show pretty much the same difference between and ASIAIR. Users of the current PS1 DR2 data should be aware of a few issues and inconsistencies in the data. The difference from J2000.0 and JNOW is about 1m (15 arc minutes) different in RA, and about 4.5 arc minutes different in DEC. If you take 52 Cygni (in the Cygnus loop) as a reference star, since it is in the region you were looking at, its J2000 coordinates (according to SkySafari) is:Īgain, according to SkySafari (with nutation and precession), JNOW (right at this moment :-) is
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