PyNOMAD is used for accessing a locally hosted copy of The Naval Observatory Merged Astrometric Dataset (NOMAD). More information on NOMAD is available at: http://www.nofs.navy.mil/nomad/
Full copies of the NOMAD catalog are large: 92Gigs uncompressed or 30Gigs when compressed with: gzip --best nomad/[0-9][0-9][0-9]/m*
The nomad.py module works with either uncompressed or compressed copies of the catalog.
A typical usage to fetch a region of the catalog is:
#!/usr/bin/env python
from nomad import fetch_nomad_box
ra_range = [281., 281.05] # RA is in degrees
dec_range = [-30.6, -30.55] # Dec is in degrees
stars = fetch_nomad_box(ra_range, dec_range, epoch=2000.0)
A typical usage to retrieve by NOMAD catalog ID is:
#!/usr/bin/env python
from nomad import fetch_star_by_nomad_id
star = fetch_star_by_nomad_id(['0594-0896798'], epoch=None)
stars = fetch_star_by_nomad_id(['0594-0896794', '0594-0896795',
'0594-0896796', '0594-0896798'], epoch=None)
Note that in all cases the returned object is a pandas.DataFrame
.
Some catalog data files used for testing the code are included in: test/data These are grabbed directly from USNO's website serving the NOMAD database: http://www.nofs.navy.mil/data/fchpix/ These can be used to perform one-time tests cross-checking that the nomad module is working correctly with the local copy of the catalog. These tests (and some other internal consistency checks) can be run by using the nomad_test.py module: python nomad_test.py
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Originally written 2013-04-05 by Henry Roe (hroe@hroe.me)