EDP Sciences
Free Access
Volume 408, Number 3, September IV 2003
Page(s) L17 - L19
Section Letters
DOI https://doi.org/10.1051/0004-6361:20031142

A&A 408, L17-L19 (2003)
DOI: 10.1051/0004-6361:20031142


Visible spectroscopy of the two largest known trans-Neptunian objects: Ixion and Quaoar

S. Marchi, M. Lazzarin, S. Magrin and C. Barbieri

Dipartimento di Astronomia, Università di Padova, Vicolo dell'Osservatorio 2, 35122 Padova, Italy
    e-mail: marchi@pd.astro.it;lazzarin@pd.astro.it;s.magrin@pd.astro.it;barbieri@pd.astro.it
(Received 10 June 2003 / Accepted 28 July 2003 )

We report visible spectroscopy of the two largest known trans-Neptunian objects (TNOs): Quaoar (=50 000) and Ixion (=28 976) obtained respectively on 4th and 5th May 2003 with the ESO New Technology Telescope (NTT) at La Silla, Chile. The spectrum of Ixion is moderately red with an absorption feature around 0.80  $\mu$m, while Quaoar is a red object with a featureless spectrum. These differences seem to indicate differences in primordial composition or dynamical history, in spite of their present similar orbits.

Key words: minor planet -- asteroids -- trans-Neptunian objects

Offprint request: S. Marchi, marchi@pd.astro.it

© ESO 2003