Astron. Astrophys. Suppl. Ser.
Volume 139, Number 1, October I 1999
|Page(s)||69 - 74|
|Published online||15 October 1999|
U B V absolute CCD photometry and differential astrometry of a sample of visual double stars with A-type primaries *,**
Royal Belgian Observatory, Ringlaan 3, B-1180 Brussels, Belgium
2 Sternberg Astronomical Institute, Universitetskii pr. 13, Moscow 119899, Russia
3 European Southern Observatory, La Silla, Chile
Send offprint request to: N. Shatsky
Accepted: 5 May 1999
We present V magnitudes, and colours of the components of 111 visual double stars and their relative position measurements ρ and θ. The primaries are of spectral class A; the angular separation is in the range. The observations were made at the 61-cm reflector of University of Toronto Southern Observatory, Chile. The obtained photometric results are of a moderate quality for absolute values ( (mag) in V and about in the and colour indices) and more precise in and , ( and , respectively). We find that about 60% of secondaries are also of spectral type A; 56% of pairs have less than . The two-colour diagram reveals significant offset of objects from the curve of unreddened Main Sequence stars. A comprehensive survey of stars in the close vicinity to the objects is also presented. The final astrometric accuracy of in ρ and in θ provides additional measurements for study of relative motion of the components.
Key words: stars: binaries: visual / techniques: photometric / astrometry
Tables 3–3 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (220.127.116.11) or via http://cdsweb.u-strasbg.fr/Abstract.html
© European Southern Observatory (ESO), 1999