121 citations · 165 across the 4 of their papers we have counts for
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astro-ph2000★ 19 cited
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…
astro-ph1996★ 10 cited
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…
astro-ph1995★ 15 cited
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--…