USNO releases first version of newest star catalog
Wednesday, April 29, 2015 - 06:01
in Astronomy & Space
The United States Naval Observatory (USNO) has released the First Edition of its USNO Robotic Astrometric Telescope star catalog, URAT1. This catalog is the follow-on to the Observatory's previous USNO CCD Astrograph Catalog (UCAC4). The new catalog contains positional data on about 228 million stars with a magnitude range of 3.0 to 18.5 for a bandpass of 680 to 750 nanometers between declinations of +89.5 degrees and -15 degrees. Longer integration times and more sensitive, backside CCDs allowed for a substantial increase in limiting magnitude, resulting in a nearly 4-fold increase in the average number of stars per square degree as compared to UCAC.