CCD photometry and new models of 5 minor planets
Abstract
We present new R filtered CCD observations of 5 faint and moderately faint asteroids carried out between October, 1998 and January, 1999. The achieved accuracy is between 0.01-0.03 mag, depending mainly on the target brightness. The obtained sinodic periods and amplitudes: 683 Lanzia - 4fh6 +/-0fh2 , 0.13 mag; 725 Amanda - >3fh0 , >=0.40 mag; 852 Wladilena - 4fh62 +/-0fh01 , 0.32 mag (December, 1998) and 0.27 mag (January, 1999); 1627 Ivar - 4fh80 +/-0fh01 , 0.77 mag (December, 1998) and 0.92 mag (January, 1999). The Near Earth Object 1998 PG unambiguously showed doubly-periodic lightcurve, suggesting the possibility of a relatively fast precession (P_1=1fh3 , P_2=5fh3 ). Collecting all data from the literature, we determined new models for 3 minor planets. The resulting spin vectors and triaxial ellipsoids have been calculated by an amplitude-method. Sidereal periods and senses of rotation were calculated for two asteroids (683 and 1627) by a modified epoch-method. The results are: 683 - lambda_p =15/195+/-25deg, beta_p =52+/-15deg, a/b=1.15+/-0.05, b/c=1.05+/-0.05, Psid = 0\fd1964156 +/- 0\fd0000001, retrograde; 852 - lambda_p =30/210 +/- 20deg, beta_p =30 +/- 10deg, a/b=2.3 +/- 0.3, b/c=1.2 +/- 0.2; 1627 - lambda_p =145/325 +/- 8deg, beta_p =34 +/- 6deg, a/b=2.0 +/- 0.1, b/c=1.09 +/- 0.05, Psid = 0\fd1999154 +/- 0\fd0000003, retrograde. The obtained shape of 1627 is in good agreement with radar images by \cite[Ostro et al. (1990)]{ost90}.
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- November 1999
- DOI:
- 10.1051/aas:1999115
- arXiv:
- arXiv:astro-ph/9909159
- Bibcode:
- 1999A&AS..140...21K
- Keywords:
-
- SOLAR SYSTEM: GENERAL MINOR PLANETS;
- Astrophysics
- E-Print:
- 8 pages, accepted for publication in Astronomy and Astrophysics Suppl. Series