Space Facts

Hipparcos Star Catalog

The earliest known stellar catalog was produced by a Greek astronomer named Hipparchus of Nicea and later Rhodes (c.190 – c.125 BCE). Sadly we do not have a copy of his catalog, but know of its existence only from the references of later astronomers. The most influential of these later astronomers was Claudius Ptolemy of Alexandria, Egypt (c.85 – c.165 CE).

On August 8, 1989, a satellite was launched to carry on the cataloging work started twenty-one centuries earlier. In honor of the Greek astronomer, the satellite was named, High Precision Parallax Collecting Satellite (HIPPARCOS). For three and a half years it measured the parallaxes and brightnesses of more than a million stars. Two catalogs were generated from the satellite's mission:

Hipparcos Star Catalog
118,000 target stars
12.5 magnitude limit
0.001 arcsecond, astrometric resolution
0.002 magnitudes, photometric resolution

Tycho Star Catalog
1 million target stars
11.5 magnitude limit
0.025 arcsecond, astrometric resolution
0.06 magnitudes, photometric resolution

Hipparchus, the man from, http://wwwhip.obspm.fr/hipparcos/SandT/hip-SandT.html
Hipparcos, the satellite from, http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Hipparchus.html