The First U.S. Naval Observatory Robotic Astrometric Telescope Catalog (URAT1)

TL;DR

URAT1 is a comprehensive astrometric catalog providing precise positions and proper motions for over 228 million objects in the northern sky, enhancing astronomical data resources.

Contribution

This paper introduces the URAT1 catalog, the first large-scale U.S. Naval Observatory astrometric catalog with high-precision data for millions of stars.

Findings

Positions accurate to 10-30 mas for over 228 million objects

Proper motions for over 188 million objects with 5-7 mas/yr errors

Catalog verified against external data sources

Abstract

URAT1 is an observational, astrometric catalog covering most of the Dec >= -15 deg area and a magnitude range of about R = 3 to 18.5. Accurate positions (typically 10 to 30 mas standard error) are given for over 228 million objects at a mean epoch around 2013.5. For the over 188 million objects matched with the 2MASS point source catalog proper motions (typically 5 to 7 mas/yr std. errors) are provided. These data are supplemented by 2MASS and APASS photometry. Observations, reductions and catalog construction are described together with results from external data verifications. The catalog data are served by CDS, Starsbourg (I/329). There is no DVD release.