WISE/NEOWISE OBSERVATIONS OF THE HILDA POPULATION: PRELIMINARY RESULTS

Journal Article · Tue Jan 10 00:00:00 EST 2012 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/744/2/197· OSTI ID:22004251

Grav, T ^[1]; Mainzer, A K; Bauer, J; Masiero, J; Eisenhardt, P R; Blauvelt, E; DeBaun, E; Elsbury, D; Gautier, T; Gomillion, S; Hand, E; Wilkins, A ^[2]; Spahr, T ^[3]; McMillan, R S ^[4]; Walker, R ^[5]; Cutri, R ^[6]; Wright, E ^[7]

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1. Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States)
2. Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)
3. Minor Planet Center, Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
4. Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)
5. Monterey Institute for Research in Astronomy, Marina, CA 93933 (United States)
6. Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States)
7. UCLA Astronomy, Los Angles, CA 90095 (United States)

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 {approx}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 p{sub V} = 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 p{sub V} = 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 p{sub V} = 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 {approx}10% of the Hildas detected in the NEOWISE survey. For the Hildas with diameter larger than 30 km, there are 67{sup +7}{sub -15}% D-type asteroids and 26{sup +17}{sub -5%} C-/P-type asteroids (with the majority of these being P-types).

• OSTI ID: 22004251
• Journal Information: Astrophysical Journal, Vol. 744, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
ALBEDO
ASTEROIDS
CLASSIFICATION
INFRARED SURVEYS
PLANETS
SOLAR SYSTEM