NEAR-INFRARED OBSERVATIONS OF COMET-LIKE ASTEROID (596) SCHEILA
- Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)
Asteroid (596) Scheila was reported to exhibit a cometary appearance and an increase in brightness on UT 2010 December 10.4. We used the IRCS spectrograph on the 8 m Subaru telescope to obtain medium-resolution spectra of Scheila in the HK band (1.4-2.5 {mu}m) and low-resolution spectra in the KL band (2.0-4.0 {mu}m) on UT 2010 December 13 and 14. In addition, we obtained low-resolution spectroscopy using the SpeX spectrograph on the 3 m NASA Infrared Telescope Facility on UT 2011 January 4 and 5. The spectrum of Scheila shows a consistent red slope from 0.8 to 4.0 {mu}m with no apparent absorption features, resembling spectra of D-type asteroids. An intimate mixing model suggests that the amount of water ice that might be present on the surface of Scheila is no more than a few percent. The spectrum of the Tagish Lake chondrite matches the asteroid's spectrum at shorter wavelengths ({lambda} < 2.5 {mu}m), but no hydration features are observed at longer wavelengths on Scheila. Our analysis corroborates other studies suggesting that the comet-like activity of Scheila is likely not caused by the sublimation of water ice. The dust coma and tail may be results of a recent impact event.
- OSTI ID:
- 21562458
- Journal Information:
- Astrophysical Journal Letters, Vol. 737, Issue 2; Other Information: DOI: 10.1088/2041-8205/737/2/L39; ISSN 2041-8205
- Country of Publication:
- United States
- Language:
- English
Similar Records
HUBBLE SPACE TELESCOPE OBSERVATIONS OF MAIN-BELT COMET (596) SCHEILA
COLLISIONAL EXCAVATION OF ASTEROID (596) SCHEILA