Astrometric masses of 21 asteroids, and an integrated asteroid ephemeris
Abstract
We apply the technique of astrometric mass determination to measure the masses of 21 main-belt asteroids; the masses of 9 Metis (1.03 ± 0.24 × 10-11 M⊙), 17 Thetis (6.17 ± 0.64 × 10-13 M⊙), 19 Fortuna (5.41 ± 0.76 × 10-12 M⊙), and 189 Phthia (1.87 ± 0.64 × 10-14 M⊙) appear to be new. The resulting bulk porosities of 11 Parthenope (12±4%) and 16 Psyche (46±16%) are smaller than previously-reported values. Empirical expressions modeling bulk density as a function of mean radius are presented for the C and S taxonomic classes. To accurately model the forces on these asteroids during the mass determination process, we created an integrated ephemeris of the 300 large asteroids used in preparing the DE-405 planetary ephemeris; this new BC-405 integrated asteroid ephemeris also appears useful in other high-accuracy applications.
- Publication:
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Celestial Mechanics and Dynamical Astronomy
- Pub Date:
- January 2008
- DOI:
- 10.1007/s10569-007-9103-8
- Bibcode:
- 2008CeMDA.100...27B
- Keywords:
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- N-body;
- Asteroid;
- Ephemerides;
- Asteroid masses;
- Astrometric masses;
- Asteroid porosity