Assigned ID: 586 ----- Submission 1 (Sat Jan 22 00:11:56 GMT 2005) ----- Recent discoveries of companions to main belt asteroids, near-Earth asteroids, Jupiter Trojans, and Kuiper belt objects, and the resulting estimates of the orbital elements and total masses of some of these systems, have challenged our expectations of the physical properties of these bodies. This new data has compelled a flurry of work on the formation and destruction processes of solar system binaries and on the overall evolution of small bodies in the solar system. Although the HST has been used successfully for some of these searches, this success has been restricted by limited HST time allocations. We propose to conduct an extensive archival search of WFPC2 and ACS images for companions to known asteroids. As of 2002, HST archival searches for asteroid trails have yielded more than 300 detections, roughly 30 of which are previously known asteroids. The ever-growing number of asteroids with well-determined orbits in the Minor Planet Center databases and an enlarged number of WFPC2 and ACS images in the Archive taken within 30 degrees of the ecliptic suggest that roughly 100 known asteroids have now been serendipitously observed by HST. The Hill spheres of these asteroids are large enough to harbor companions that could be resolved with HST. This archival search will allow us to measure the binary fraction of asteroids in a size range that is out of reach of ground-based AO observations and which has been largely unexplored in targeted HST searches. Although serendipitous observations of asteroids are often significantly trailed, the signal from the asteroid and any possible companion can be concentrated by summing the pixels along the asteroid trail, a modification of the technique used by Bernstein et al. (2004) to detect faint Kuiper belt objects. The accurate ephemerides of these asteroids will permit any asteroid binaries that are detected to be re-observed with targeted observations, in order to determine their binary orbital parameters.

SOLAR SYSTEM 12 64744 false 0.0 false false false false false SUPPORTED