A&AS Supplement Series, Vol. 126, November II 1997, 169-176
Received September 24, 1996; accepted January 3, 1997
V.A.F. Martin
- N.V. Leister
Send offprint request: V.A.F. Martin
Instituto Astronômico e Geofísico,
Universidade de São Paulo, CP 9638, 01065-970 São
Paulo, SP,
Brazil
Observatoire de la Côte d'Azur/C.E.R.G.A.,
Avenue Copernic, F-06130 Grasse, France
We show the results of an evaluation
of a global reduction
method for Danjon astrolabe observations. The approach is much
simpler
but more
precise than the conventional method.
The new form of the equations gives us the possibility of using
the entire
set of an observational programme using the data from different
catalogues
taken at two zenith distances (
and 
).
The observational programme contains about 15000 observations of
381
different stars taken at the "Observatório Abrahão de
Moraes"
(OAM, 
= 
00
06
S;
= 
W), Valinhos, São Paulo,
Brazil.
The reduction was based on the FK5 system. We discuss the
possibility to compute
absolute declinations through the stars belonging simultaneously
to the
and zenith distance programmes. The absolute
declination corrections were determined for 269 stars with a
precision of
0.13, and the value of the determined equator correction
is
0.028 
0.034. The instrumental effects were
also determined.
keywords: astrometry -- astrolabe -- reference system -- fundamental stars and other objects