ASTEROID 83-BEATRIX - PHOTOMETRY AND MODEL

Asteroid 83 Beatrix was observed on 30 nights during five oppositions: 1984 (Lowell Observatory, Arizona), 1986, 1988, 1990, and 1991 (Khark iv, Ukraine). A new value of the synodical period was found to be 10.1 08 hours. The phase curves at the 1984 and 1988 apparitions (H = 8.69, G = 0.20) seem to differ from those resulting from 1986 and 1990 obse rvations (H = 8.58, G = 0.15). The difference may be caused by the cha nging aspect of the asteroid. Using all available lightcurves we have found that Beatrix is a retrograde rotator with a sidereal period of 0 .4213796 +/- 0.0000005 days and the ecliptic coordinates (B1950.0) of its north pole are (3 degrees, -37 degrees) or - according to the seco nd solution - (172 degrees, -31 degrees). An asteroid shape has been a pproximated by a triaxial ellipsoid with the semiaxis ratios a/b = 1.2 6, b/c = 1.16.