WISE/NEOWISE Observations of the Hilda Population: Preliminary Results
Abstract
We present the preliminary analysis of 1023 known asteroids in the Hilda region of the solar system observed by the NEOWISE component of the Wide-field Infrared Survey Explorer (WISE). The sizes of the Hildas observed range from ~3 to 200 km. We find no size-albedo dependency as reported by other projects. The albedos of our sample are low, with a weighted mean value of pV = 0.055 ± 0.018, for all sizes sampled by the NEOWISE survey. We observed a significant fraction of the objects in the two known collisional families in the Hilda population. It is found that the Hilda collisional family is brighter, with a weighted mean albedo of pV = 0.061 ± 0.011, than the general population and dominated by D-type asteroids, while the Schubart collisional family is darker, with a weighted mean albedo of pV = 0.039 ± 0.013. Using the reflected sunlight in the two shortest WISE bandpasses, we are able to derive a method for taxonomic classification of ~10% of the Hildas detected in the NEOWISE survey. For the Hildas with diameter larger than 30 km, there are 67+7 - 15% D-type asteroids and 26+17 - 5% C-/P-type asteroids (with the majority of these being P-types).
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 2012
- DOI:
- 10.1088/0004-637X/744/2/197
- arXiv:
- arXiv:1110.0283
- Bibcode:
- 2012ApJ...744..197G
- Keywords:
-
- infrared: planetary systems;
- minor planets;
- asteroids: general;
- surveys;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- Accepted for publication in Astrophysical Journal. Electronic table to be published on the publishers website