Lightcurves of Centaurs 2000 QC and 2001 PT

¹ Instituto de Astrofísica de Andalucia, CSIC, Granada, Spain
² Institut d'Optique Théorique et Appliquée, 91403 Orsay, France
³ Centre for Astronomy and Astrophysics of the University of Lisbon / Lisbon Astronomical Observatory, Tapada da Ajuda, 1349-018 Lisbon, Portugal e-mail: roos@oal.ul.pt

Corresponding author: J. L. Ortiz, ortiz@iaa.es

Received: 4 February 2002
Accepted: 28 March 2002

Abstract

We present CCD photometric observations of Centaurs 2000 QC₂₄₃ and 2001 PT₁₃. For 2000 QC₂₄₃, a large amplitude period is found at , which likely corresponds to half the rotation period of the body, or coincides with the full rotation period, depending on whether the variability is induced by an irregular shape or by albedo features. The apparent double-peaked lightcurve favors the first interpretation. The large amplitude of the oscillations imply a very irregular shape for this object or a large albedo assymmetry between the two hemispheres. For 2001 PT₁₃, a clear period of was detected, with an amplitude of 0.16 mag. Since 4.15 h is close to the breakup limit for typical cometary densities and tensile strengths, 8.3 h appears to be a more likely rotation period.