CCD photometry, spin and shape model of the asteroid 1572 Posnania

T. Michalowski (1) , W. Pych (2) , T. Kwiatkowski (1) , A. Kryszczynska (1) , P. Pravec (3) , W. Borczyk (1) , Anders Erikson (4) , W. Wisniewski (5) , François Colas (6) , Jerôme Berthier (6)

1 UAM - Uniwersytet im. Adama Mickiewicza w Poznaniu = Adam Mickiewicz University in Poznań
2 CAMK - Centrum Astronomiczne im. M. Kopernika, Warszawa
3 Astronomy Institute of the Academy of Sciences, Ondrejov, Czech Republic
4 Institute of Space Sensor Technology and Planetary Exploration [Berlin]
5 LPL - Lunar and Planetary Laboratory [University of Arizona]
6 IMCCE - Institut de Mécanique Céleste et de Calcul des Ephémérides

Lightcurves of the asteroid 1572 Posnania were obtained at six observatories on 19 nights during four apparitions: in 1993, 1994-95, 1996, and 1999. The synodical period is found to be 8.048 hours and the observed amplitudes of brightness variations are in the range of 0.37-0.40 mag. The sense of rotation is retrograde with a sidereal period P_sid = 0.3353931 /- 0.0000003 days. The ecliptic coordinates of the pole of this asteroid are lambda_p = 46^deg /- 6^deg and beta_p = -65^deg /- 5^deg. The shape of Posnania can be approximated by a triaxial ellipsoid model with semiaxes ratios a/b = 1.35 /- 0.01 and b/c = 1.04 /- 0.03. Partly based on observations collected at the European Southern Observatory, La Silla, Chile.

Domaines: Astrophysique [astro-ph]

T. Michalowski, W. Pych, T. Kwiatkowski, A. Kryszczynska, P. Pravec, et al.. CCD photometry, spin and shape model of the asteroid 1572 Posnania. Astronomy and Astrophysics - A&A, 2001, 371, pp.748-752. ⟨10.1051/0004-6361:20010372⟩. ⟨hal-03729598⟩