EDP Sciences
Free access
Volume 408, Number 1, September II 2003
Page(s) 379 - 385
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361:20030663

A&A 408, 379-385 (2003)
DOI: 10.1051/0004-6361:20030663

UBV photometry of the asteroid 44 Nysa

F. A. Tupieva

Institute of Astrophysics, Tajik Academy of Sciences, and Isaac Newton Institute of Chile, Tajikistan Branch, Bukhoro Str. 22, Dushanbe 734042, Tajikistan
(Received 10 June 2002 / Accepted 30 April 2003)

The color curves of Nysa connected to the rotation and phase angle were obtained from observations for the first time in 1982. The color curves showed the  U-B change with rotation. The value of this change was 0.2 mag. Color variation indicates that the extended color spot is on the surface of 44 Nysa. The U-B color index decreases with the increase of the phase angle (the phase coefficient is 0.011 mag/deg). This decrease is stronger for the surface with color spots. Phase functions of the brightness for opposite sides of Nysa are different. The value of the opposition effect of 44 Nysa decreases as reflectance decreases.

Key words: minor planets, asteroids -- star system: general -- techniques: photometric

© ESO 2003