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The AXAF Guide and Acquisition Star Catalog

An all-sky astrometric and photometric catalog
prepared for the operation of Chandra
(formerly AXAF). version 1.7 December 2018

Chandra's Aspect Camera Assembly (ACA) measures positions of selected stars to acquire and hold target pointings, and for post facto aspect determination. Guide stars are selected from the AGASC. Based originally on version 1.1 of the Guide Star Catalog for the Hubble Space Telescope, the AGASC has been extended and refined to include colors and to improve astrometric information. AGASC merges multiple entries and combines the best data from Tycho-2 and GSC-ACT to include one entry per star down to V~14.5. The AGASC also includes ACA mag predictions based on colors, as well as additional information on crowding of each star, pertinent to guide star quality. 2MASS data identify nearby galaxies down to J=12.5.


RA: dec: radius:
ddd.ddddd
or
hh:mm:ss.sss
sdd.ddddd
or
sdd:mm:ss.sss
arcmin
max 30

AGASC1.5: ADASS 2002 paper and AGASC 1.7: Detailed Information

Links to Constituent Catalogs
GSC-ACT catalog: info and search
Tycho-2 catalog: info and search
2MASS catalog: info and archive(IRSA)


The full 2.6 Gigabyte AGASC1.7 catalog is also available: contact aspect_help@cfa.harvard.edu if you need the full catalog for your work. No portable catalog reading software is available, but the 9537 individual FITS files can be accessed with e.g., FTOOLS.







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