Main belt binary asteroidal systems with circular mutual orbits
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×R) 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/cm 3) 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/cm 3, derived based on IRAS radiometric size measurement. We compare the characteristics of these orbits in the light of tidal-effect evolution.
- Publication:
-
Icarus
- Pub Date:
- July 2008
- DOI:
- 10.1016/j.icarus.2008.03.007
- arXiv:
- arXiv:0804.1383
- Bibcode:
- 2008Icar..196...97M
- Keywords:
-
- Astrophysics
- E-Print:
- 72 pages, 9 tables, 4 figures