A portrait of the extreme solar system object 2012 DR30 (original) (raw)

A&A 555, A3 (2013)

1, Gy. Szabó1,2,3, J. Horner4, B. C. Conn5, T. G. Müller6, E. Vilenius6, K. Sárneczky1,2, L. L. Kiss1,2,7, M. Bannister8, D. Bayliss8, A. Pál1,9, S. Góbi1, E. Verebélyi1, E. Lellouch10, P. Santos-Sanz11, J. L. Ortiz11, R. Duffard11 and N. Morales11

1 Konkoly Observatory, MTA CSFK, 1121 Budapest, Konkoly Th. M. út 15–17, Hungary
e-mail: pkisscs@konkoly.hu
2 ELTE Gothard–Lendlet Research Group, 9700 Szombathely, Szent Imre herceg út 112, Hungary
3 Dept. of Exp. Physics & Astronomical Observatory, University of Szeged, 6720 Szeged, Hungary
4 Department of Astrophysics, School of Physics, University of New South Wales, Sydney, NSW 2052, Australia
5 Max-Planck–Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
6 Max-Planck–Institut für extraterrestrische Physik, Giessenbachstrasse, 85748 Garching, Germany
7 Sydney Institute for Astronomy, School of Physics, A28, The University of Sydney, NSW 2006, Australia
8 Research School of Astronomy and Astrophysics, the Australian National University, ACT 2612, Australia
9 Department of Astronomy, Loránd Eötvös University, Pázmány Péter sétány 1/A, 1119 Budapest, Hungary
10 Observatoire de Paris, Laboratoire d’Études Spatiales et d’Instrumentation en Astrophysique (LESIA), 5 place Jules Janssen, 92195 Meudon Cedex, France
11 Instituto de Astrofísica de Andalucía (IAA–CSIC) Glorieta de la Astronomía, s/n 18008 Granada, Spain

Received: 22 January 2013
Accepted: 25 April 2013

Abstract

2012 DR30 is a recently discovered solar system object on a unique orbit, with a high eccentricity of 0.9867, a perihelion distance of 14.54 AU, and a semi-major axis of 1109 AU, in this respect outscoring the vast majority of trans-Neptunian objects (TNOs). We performed Herschel/PACS and optical photometry to uncover the sizeand albedo of 2012 DR30, together with its thermal and surface properties. The body is 185 km in diameter and has a relatively low _V_-band geometric albedo of ~8%. Although the colours of the object indicate that 2012 DR30 is an RI taxonomy class TNO or Centaur, we detected an absorption feature in the _Z_-band that is uncommon among these bodies. A dynamical analysis of the target’s orbit shows that 2012 DR30 moves on a relatively unstable orbit and was most likely only recently placed on its current orbit from the most distant and still highly unexplored regions of the solar system. If categorised on dynamical grounds 2012 DR30 is the largest Damocloid and/or high inclination Centaur observed so far.

Key words: Kuiper belt: general / Kuiper belt objects: individual: 2012 DR30

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Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.