Microlens Surveys are a Powerful Probe of Asteroids
Abstract
While of order of a million asteroids have been discovered, the number in rigorously controlled samples that have precise orbits and rotation periods, as well as well-measured colors, is relatively small. In particular, less than a dozen main-belt asteroids with estimated diameters D < 3 km have excellent rotation periods. We show how existing and soon-to-be-acquired microlensing data can yield a large asteroid sample with precise orbits and rotation periods, which will include roughly 6% of all asteroids with maximum brightness I < 18.1 and lying within 10° of the ecliptic. This sample will be dominated by small and very small asteroids, down to D ~ 1 km. We also show how asteroid astrometry could turn current narrow-angle OGLE proper motions of bulge stars into wide-angle proper motions. This would enable one to measure the proper-motion gradient across the Galactic bar.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 2013
- DOI:
- 10.1088/0004-637X/767/1/42
- arXiv:
- arXiv:1301.6165
- Bibcode:
- 2013ApJ...767...42G
- Keywords:
-
- gravitational lensing: micro;
- minor planets;
- asteroids: general;
- Astrophysics - Earth and Planetary Astrophysics;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 20 pages, 2 figures. ApJ in press