Portal de Periódicos da CAPES

Artigo Acesso aberto Produção Nacional Revisado por pares

BIBTEX RIS

Absolute declinations with the photoelectric astrolabe at Calern Observatory (OCA)

1999; EDP Sciences; Volume: 137; Issue: 2 Linguagem: Inglês

10.1051/aas

1286-4846

Vera Aparecida Fernandes Martin, N. V. Leister, G. Vigouroux, M Furia, A. Journet,

Historical Geography and Cartography

A regular observational programme with a photoelectric astrolabe have been performed at "Observatoire du Calern" (Observatoire de la Côte d'Azur, OCA, ϕ = ; λ = , Calern, Caussols, France) for the last twenty years. It has been almost fully automatized between 1984 and 1987. Since 1988 the photoelectric astrolabe was used without any modification. In addition to determining the daily orientation of the local vertical, the yearly analysis of the residuals permits to derive corrections to the used star catalogue (Vigouroux et al. 1992). A global reduction method was applied for the ASPHO observations. The new form of the equations (Martin & Leister 1997) give us the possibility of using the entire set of the observing program using data taken at two zenith distances (30o and 45o). The program contains about 41648 stars' transits of 269 different stars taken at "Observatoire du Calern" (OCA). The reduction was based on the HIPPARCOS system. We discuss the possibility of computing absolute declinations through stars belonging simultaneously to the 30o and 45o zenith distances programmes. The absolute declination corrections were determined for 185 stars with precision of 0.027″ and the value of the determined equator correction is -0.018 ″ ± 0.005″. The instrumental effects were also determined. The mean epoch is 1995.29.