No CrossRef data available.
Published online by Cambridge University Press: 25 May 2016
The Version 1.0 of the U.S. Naval Observatory Twin Astrographic Catalog (TAC) contains positions of 705,679 stars (Zacharias et al. 1996). The TAC 1.0 covers over 90% of the sky from +90° to −18° declination; 260 out of 5180 plates are not yet measured. Plates were taken in both the yellow (508-578 nm) and in the blue (410-486 nm) bandpass between 1978 and 1986 at the U.S. Naval Observatory (USNO) in Washington, DC.