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 200km. 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 30km, there are 67+7 - 15% D-type asteroids and 26+17 - 5% C-/P-type asteroids (with the majority of these being P-types).
- infrared: planetary systems
- minor planets, asteroids: general
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science