Visible and near-infrared spectroscopy of the Centaur 32532 (2001 PT)^*

ESO Large Program on TNOs and Centaurs: First spectroscopy results

¹ LESIA, Observatoire de Paris, 92195 Meudon Pricipal Cedex, France e-mail: alain.doressoundiram@obspm.fr; jennifer.romon@obspm.fr; catherine.debergh@obspm.fr
² European Southern Observatory ESO, Alonso de Cordova 3107, Santiago de Chile, Chile e-mail: hboehnha@eso.org; adelsant@eso.org; ohainaut@eso.org
³ INAF, Osservatorio Astronomico di Torino, Strada Osservatorio 20, 10025 Pino Torinese, Italy e-mail: dotto@to.astro.it
⁴ INAF, Osservatorio Astronomico di Roma, via Frascati 33, 00040 Monteporzio Catone, Italy
⁵ Astronomical Department of Padova, Vicolo dell' Osservatorio 2, 35122 Padova, Italy e-mail: lazzarin@pd.astro.it; fornasier@pd.astro.it
⁶ INAF, Osservatorio astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy e-mail: tozzi@arcetri.astro.it
⁷ Institute for Astronomy, Universidad Catolica del Norte, Antofagasta, Chile e-mail: lbarrera@ucn.cl
⁸ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany e-mail: birkle@mpi-hd.mpg.de
⁹ IFA, University of Hawaii, 2680 Woodlawn Drive, Honolulu, Hawaii 96822, USA e-mail: meech@ifa.hawaii.edu
¹⁰ Instituto de Astrofisica de Andalucia CSIC, PO Box 3004, 18080 Granada, Spain e-mail: ortiz@iaa.es
¹¹ National Astronomical Observatory, Osawa 2-21-1, Mitaka, Tokyo, Japan e-mail: sekigchtm@nao.ac.jp; jun.watanabe@nao.ac.jp
¹² Max-Planck-Institut für Aeronomie, Postfach 20, 37189 Katlenburg-Lindau, Germany e-mail: thomas@linmpi.mpg.de
¹³ European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching, Germany e-mail: rwest@eso.org
¹⁴ Astronomy Technology Centre, Blackford Hill, Edinburgh EH9 3HJ, UK e-mail: j.davies@roe.ac.uk

Corresponding author: M. A. Barucci, antonella.barucci@obspm.fr

Received: 6 May 2002
Accepted: 20 June 2002

Abstract

We present photometric and spectroscopic data obtained through visible and near-infrared observations of the Centaur 32532 (2001 PT13) performed with FORS1 and ISAAC at the Very Large Telescope (VLT-ESO) within the framework of an ESO large program on the Trans-Neptunian objects (TNOs) and Centaurs. The results show evidence for a difference in the near-infrared spectral behaviour obtained during two observations carried out one month apart. In one spectrum there is the possible presence of signatures of water ice in small amounts. Two models have been proposed to interpret the surface composition of this Centaur.