121 citations · 165 across the 4 of their papers we have counts for
4 papers
The First U.S. Naval Observatory Robotic Astrometric Telescope Catalog (URAT1)
Norbert Zacharias, Charlie Finch, John Subasavage +14
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 sta…
Comparing Tycho-2 Astrometry with UCAC1
Norbert Zacharias, Marion I. Zacharias, Sean E. Urban +1
The Tycho-2 Catalogue, released in February 2000, is based on the ESA Hipparcos space mission data and various ground-based catalogs for proper motions. An external comparison of t…
The Twin Astrographic Catalog (TAC) Version 1.0
N. Zacharias, M. I. Zacharias, G. G. Douglass +1
A first version of the Twin Astrographic Catalog (TAC) of positions for 705,679 stars within has been produced. The sky coverage of the TAC is com…
A Radio--Optical Reference Frame VIII. CCD observations from KPNO and CTIO: internal calibration and first results
N. Zacharias, C. de Vegt, L. Winter +1
In this pilot investigation, precise optical positions in the FK5 system are presented for a set of 16 compact extragalactic radio sources, which will be part of the future radio--…