Discovery of a Satellite to Asteroid Family Member (702) Alauda
Abstract
Rojo and Margot [1] reported the discovery of a satellite to (702) Alauda from adaptive-optics imaging with the European Southern Observatory (ESO) 8-m Very Large Telescope (VLT) on Cerro Paranal, Chile. (702) Alauda (a = 3.2 AU, e = 0.02, i = 21 deg) has been identified as the largest member of a dynamical family [2,3], suggesting a possible origin of the satellite in the family formation event.
The diameter of (702) Alauda is given in the IRAS Minor Planet Survey (IMPS) as 194.73 +/- 3.2 km [4]. If the primary and secondary have similar albedoes, the diameter of the satellite is about 5.5 km. This is based on the measured flux ratio between primary and secondary of 1250, possibly the largest ever observed for solar system binaries with adaptive optics. This is the first satellite discovered to a large minor planet of type B in the SMASSII taxonomy, which is defined by a linear featureless spectrum with bluish to neutral slope [5]. B-types are carbonaceous asteroids that are not well characterized. The mass and density estimates of B-type (2) Pallas vary by 50% [6,7]. Our ongoing determination of the satellite orbit will provide mass and density estimates for (702) Alauda. [1] Rojo and Margot, CBET 1016, 2007. [2] Foglia and Masi 2004, Minor Planet Bull. 41, 100. [3] Gil-Hutton 2006, Icarus 183, 93. [4] Tedesco 2002, AJ 123, 1056. [5] Bus and Binzel 2002, Icarus 158, 146. [6] Hilton 2002, Asteroids III, 103. [7] Britt et al. 2002, Asteroids III, 485.- Publication:
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AAS/Division for Planetary Sciences Meeting Abstracts #39
- Pub Date:
- October 2007
- Bibcode:
- 2007DPS....39.1608M