The rotational and physical properties of the Centaur (32532) 2001 PT13

We present observations of the Centaur (32532) 2001 PT13 taken between September 2000 and December 2000. A multi-wavelength lightcurve was assembled from V-, R- and J-band photometry measurements. Analysis of the lightcurve indicates that there are two peaks of slightly different brightness, a rotation period of 0.34741±0.00005 day, and a maximum photometric range of 0.18 mag. We obtained VRJHK colors (V–R=0.50±0.01, V–J=1.69±0.02, V–H=2.19±0.04, and V–K=2.30±0.04) that are consistent with the grey KBO/Centaur population. The V–R color shows no variation as a function of rotational phase; however, we cannot exclude the possibility that rotational variations are present in the R–J color. Assuming a 4% albedo, we estimate that 2001 PT13 has an effective diameter of 90 km and a minimum axial ratio a/b of 1.18. We find no evidence of a coma and place an upper limit of 15 g s−1 on the dust production rate.