EDP Sciences
Free access
Volume 407, Number 2, August IV 2003
Page(s) L37 - L40
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20031066

A&A 407, L37-L40 (2003)
DOI: 10.1051/0004-6361:20031066


New spin period determination for comet 6P/d'Arrest

P. J. Gutiérrez1, J. de León2, L. Jorda1, J. Licandro3, L. M. Lara4 and P. Lamy1

1  Laboratoire d'Astrophysique de Marseille, BP 8, 13376 Marseille Cedex 12, France
2  Instituto de Astrofísica de Canarias, C/Via Lactea s/n, 38200 La Laguna, Tenerife, Spain
3  Isaac Newton Group of Telescopes & Instituto de Astrofísica de Canarias, PO Box 321, 38700 Santa Cruz de La Palma, Tenerife, Spain
4  Instituto de Astrofísica de Andalucía, CSIC, PO Box 3004, 18080 Granada, Spain

(Received 22 May 2003 / Accepted 3 July 2003)

A lightcurve of comet 6P/d'Arrest from R-band CCD images taken at La Palma 2.52 m NOT telescope is presented. The lightcurve shows noticeable periodic changes in brightness produced by rotational modulation. The periodogram analysis of the lightcurve shows a peak with a confidence level exceeding 99.9% at 3.336 h. Assuming an elongated nucleus, the most likely spin period is therefore 6.67 $\pm$ 0.03 h, but other periodicities are also possible. The peak to peak amplitude is 0.082 $\pm$ 0.016 mag. This period, and the other peaks detected in the periodogram, are not commensurable with previous estimates of the spin period of comet 6P/d'Arrest. If all the measurements are correct, the differences between this estimate and the previous ones could be due to a possible change in the spin period of comet 6P/d'Arrest or to this comet being rotating in a complex mode.

Key words: comets: individual: 6P/d'Arrest

Offprint request: P. J. Gutiérrez, pedro.gutierrez@oamp.fr

© ESO 2003