Complete text (abstract only):
Since 1996 we have been regularly observing with a CCD micrometer transit
circle
at the Abrahno de Moraes Observatory in
Valinhos, Brazil. The new
detector system is the result of a successful cooperation with the
Bordeaux Observatory. Differential astrometric and photometric
observations of more than ten thousand stars per clear night, down
to V = 16 mag, become feasible, making possible the current
development of many observational projects:
Here, we presented the light curve of the source 2005-489 (BL Lac)
observed in 1997, that shows variability, as well as the differences
between the CCD and radio positions for 14 bright extragalactic
objects (ICRF). We present too the comparison between our Pluto
positions and the ephemeris DE403 and DE405 for 1996 and 1997. The
mean differences (CCD DE405) obtained were:
1996 | 1997 | |
Righ Ascension | -0.05 ± 0.06 arcsec | -0.01 ± 0.03 arcsec |
Declination | +0.01 ± 0.03 arcsec | -0.06 ± 0.04 arcsec |
Bibliographical details:
Ramachrisna Teixeira, Paulo Benevides-Soares, Tania P. Dominici, Wilson Monteiro, Michel Rapaport, J. François Le Campion, Yves Réquième: CCD meridian observations at Valinhos Observatory. In: Peter Brosche, Wolfgang R. Dick, Oliver Schwarz, Roland Wielen (Eds.): The Message of the Angles - Astrometry from 1798 to 1998. Proceedings of the International Spring Meeting of the Astronomische Gesellschaft, Gotha, May 11-15, 1998. (Acta Historica Astronomiae ; 3). Thun ; Frankfurt am Main : Deutsch, 1998, p. 190.
Html-Version: Wolfgang R. Dick. Created: 21 Jan 1999