|
|||||
|
|
Low phase angle effects in photometry of trans-neptunian objects: 20000 Varuna and 19308 (1996 TO66) |
|
| Authors: | IN Belskaya JL Ortiz V Ivanova VG Shevchenko |
| Institution: | a Observatoire de Besançon, 25000 Besançon, France b Astronomical Institute of Kharkiv National University, Sumska str. 35, Kharkiv 61022, Ukraine c Instituto de Astrofísica de Andalucía, CSIC, Apt 3004, 18080 Granada, Spain d Institute of Astronomy, Bulgarian Academy of Sciences, BG-1784 Sofia, Bulgaria e GAUC, Observatório Astronómico da Universidade de Coimbra, P-3040 Coimbra, Portugal |
| Abstract: | We present the results of photometric observations of trans-neptunian object 20000 Varuna, which were obtained during 7 nights in November 2004-February 2005. The analysis of new and available photometric observations of Varuna reveals a pronounced opposition surge at phase angles less than 0.1 deg with amplitude of 0.2 mag relatively to the extrapolation of the linear part of magnitude-phase dependence to zero phase angle. The opposition surge of Varuna is markedly different from that of dark asteroids while quite typical for moderate albedo Solar System bodies. We find an indication of variations of the scattering properties over Varuna's surface that could result in an increase of the lightcurve amplitude toward zero phase angle. It is shown that a similar phase effect can be responsible for lightcurve changes found for TNO 19308 (1996 TO66) in 1997-1999. |
| Keywords: | Trans-neptunian objects Asteroids Photometry |
| 本文献已被 ScienceDirect 等数据库收录！ | |