EDP Sciences
Free access
Volume 376, Number 1, September II 2001
Page(s) 310 - 315
Section The solar system
DOI http://dx.doi.org/10.1051/0004-6361:20010934

A&A 376, 310-315 (2001)
DOI: 10.1051/0004-6361:20010934

Photometric and spectroscopic observations of Sycorax, satellite of Uranus

J. Romon1, C. de Bergh1, M. A. Barucci1, A. Doressoundiram1, J.-G. Cuby2, A. Le Bras1, 3, S. Douté4 and B. Schmitt4

1  Observatoire de Paris, Meudon, France
2  ESO, Chile
3  IAS, Orsay, France
4  Lab. de Planétologie de Grenoble, St Martin d'Hères, France

(Received 9 May 2001 / Accepted 26 June 2001)

Sycorax is the brightest of the five irregular Uranian satellites recently discovered. These satellites are supposed to be captured bodies. We present visible and near-infrared photometry, as well as near-infrared spectroscopy of Sycorax. The overall shape of the spectrum is quite puzzling: it has a red slope in the visible (such as Centaurs and Transneptunian objects), whereas the reflectivity strongly decreases beyond 1 $\mu$m and is rather flat over the near-infrared range. We were not able to reproduce the spectral behaviour of Sycorax using simple materials. A rotational effect is suggested to explain the shape of the spectrum. BVRIJ magnitudes have been measured over a period of 1 hour, with five V measurements which do not show any strong variation. So only a strong change in the magnitude between the V measurements and the J measurement (30 min later) could explain the shape of the spectrum, but further investigation is required to conclude.

Key words: planets and satellites: general -- planets and satellites: individual: Sycorax

Offprint request: J. Romon, jennifer.romon@obspm.fr

SIMBAD Objects

© ESO 2001