Northern Hemisphere observations of ICRF sources on the USNO stellar catalogue frame

¹ Institut de Mécanique Céleste et de Calcul des Éphémérides (IMCCE) – Observatoire de Paris, UMR 8028 du CNRS, 77 avenue Denfert-Rochereau, 75014 Paris, France
² Grupo de Estudos em Astronomia–OV/UFRJ and Observatório Nacional/MCT, R. Gal. José Cristino 77, S. Cristovão, Rio de Janeiro, Brasil

Corresponding author: A. Fienga, fienga@imcce.fr

Received: 21 July 2003
Accepted: 4 November 2003

Abstract

The most recent USNO stellar catalogue, the USNO B1.0 (Monet et al. [CITE]), provides positions for 1 042 618 261 objects, with a published astrometric accuracy of 200 mas and five-band magnitudes with a 0.3 mag accuracy. Its completeness is believed to be up to magnitude 21th in V-band. Such a catalogue would be a very good tool for astrometric reduction. This work investigates the accuracy of the USNO B1.0 link to ICRF and give an estimation of its internal and external accuracies by comparison with different catalogues, and by computation of ICRF sources using USNO B1.0 star positions.