Diameters and albedos of three sub-kilometer Near Earth Objects derived from Spitzer observations

Abstract

Near Earth Objects (NEOs) are fragments of remnant primitive bodies that date from the era of Solar System formation. At present, the physical properties and origins of NEOs are poorly understood. We have measured thermal emission from three NEOs -- (6037) 1988 EG, 1993 GD, and 2005 GL -- with Spitzer's IRAC instrument at 3.6, 4.5, 5.8, and 8.0 microns (the last object was detected only at 5.8 and 8.0 microns). The diameters of these three objects are 400 m, 180 m, and 160 m, respectively, with uncertainties of around 20% (including both observational and systematic errors). For all three the geometric albedos are around 0.30, in agreement with previous results that most NEOs are S-class asteroids. For the two objects detected at 3.6 and 4.5 microns, diameters and albedos based only on those data agree with the values based on modeling the data in all four bands. This agreement, and the high sensitivity of IRAC, show the promise of the Spitzer Warm Mission for determining the physical parameters for a large number of NEOs.

arXiv commentApJL in press

References in corpus (5)

• The Infrared Array Camera (IRAC) for the Spitzer Space Telescope
• The Spitzer Space Telescope Mission
• Absolute Calibration of the Infrared Array Camera on the Spitzer Space Telescope
• Thermal inertia of near-Earth asteroids and implications for the magnitude of the Yarkovsky effect
• Thermal infrared observations of the Hayabusa spacecraft target asteroid 25143 Itokawa

Cited by in corpus (4)

• The spectrum of the recycled PSR J0437-4715 and its white dwarf companion
• NEOSurvey 1: Initial results from the Warm Spitzer Exploration Science Survey of Near Earth Object Properties
• Asteroid Distributions in the Ecliptic
• Infrared Lightcurves of Near Earth Objects