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arXiv · 0804.1383

Main Belt Binary Asteroidal Systems With Circular Mutual Orbits

F. Marchis·P. Descamps·M. Baek·A. W. Harris·M. Kaasalainen·J. Berthier·D. Hestroffer·F. Vachier
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Abstract

In 2003, we initiated a long-term adaptive optics campaign to study the orbit of various main-belt asteroidal systems. Here we present a consistent solution for the mutual orbits of four binary systems: 22 Kalliope, 45 Eugenia, 107 Camilla and 762 Pulcova. With the exception of 45 Eugenia, we did not detect any additional satellites around these systems although we have the capability of detecting a loosely-bound fragment (located at 1/4 x RHill) that is ~40 times smaller in diameter than the primary. The common characteristic of these mutual orbits is that they are roughly circular. Three of these binary systems belong to a C-"group" taxonomic class. Our estimates of their bulk densities are consistently lower (~1 g/cm3) than their associated meteorite analogs, suggesting an interior porosity of 30-50% (taking CI-CO meteorites as analogs). 22 Kalliope, a W-type asteroid, has a significantly higher bulk density of ~3 g/cm3, derived based on IRAS radiometric size measurement. We compare the characteristics of these orbits in the light of tidal-effect evolution.

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F. Marchis, P. Descamps, M. Baek, A. W. Harris, M. Kaasalainen, J. Berthier, D. Hestroffer, F. Vachier. 2008-04-09. Main Belt Binary Asteroidal Systems With Circular Mutual Orbits. https://doi.org/10.1016/j.icarus.2008.03.007

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