Is astrometry.net suitable for Minor Planet astrometry?

[Ferran Casarramona]

Hi,

I'm using astrometry.net via AstroImageJ software. Congratulations! This is a very usefull service.

I'm trying to do some minor planets and comets astrometry and report it to Minor Planet Center (MPC).
I'm wonder if astrometry.net has used in this way with succes.

Also, which catalogs are used in order to solve the plates? This is a data requested by MPC in order to report.

Thanks,
  Ferran Casarramona

[Dustin Lang]

Hi,

I don't know if anyone has used it for MPC.

The web service, nova.astrometry.net, uses USNO-B1 for narrow-field images.  It also has some Tycho-2 based index files, but those are only used for wide-field.

If you download the "4200-series" index files to the "solve-field" program on your computer, those use the 2MASS catalog.

cheers,
--dustin

[Ferran Casarramona]

AstroImageJ solves via nova.astrometry.net web.


For example, in this submission http://nova.astrometry.net/status/480656 the wcs.fits file shows this lines like this:
COMMENT Index(0): /data1/INDEXES/200-current/index-219.fits
...
COMMENT Index(75): /data1/INDEXES/4200/index-4200-21.fits                      
COMMENT Index(76): /data1/INDEXES/4100/index-4119.fits                         
...
COMMENT Index(88): /data1/INDEXES/4100/index-4107.fits

This means plate-solving used USNO-B1 and 2MASS catalogs? Or nova.astrometry.net only uses USNO-B1?

Thanks,
  Ferran

[Dustin Lang]

At the bottom of the log file you'll see:

Field 1: solved with index index-4108.fits.

so it tried to solve your image using all those index files, but it actually found a solution in the one based on Tycho-2.

cheers,
--dustin

[Ferran Casarramona]

Thank you Dustin,

I realized than MPC recomends UCAC-4 catalog, which includes also Tycho-2 catalog. So, it's fine for my purpouses.
MPC request to report which catalog is used, so if your set of catalogs can be considered a catalog and it has a name, I could ask MPC to
add it as accepted catalog for astrometry.

Regards,
  Ferran

[Dustin Lang]

If you want to run the code on your own computer, you could download only the "4100-series", http://data.astrometry.net/4100/, which are from Tycho-2.

Note that any single image will be solved using a single catalog.  Basically, we look for a match in all available catalogs, but once we find a match we use only that catalog.

cheers,
--dustin

[Ferran Casarramona]

Just for the records.

I sucessfully send astrometrical observations to MPC calibrating with AstroImageJ which uses astrometry.net