Potentially Hazardous Asteroid 2004 XP 14 Constraining Albedo

Potentially Hazardous Asteroid 2004 XP 14: Constraining Albedo, Diameter, & Taxonomy Target of Opportunity, NASA IRTF V. Reddy, M. J. Gaffey, P. S. Hardersen, S. Kumar, University of North Dakota, Grand Forks. P. A. Abell, NASA Johnson Space Center, Houston.

Albedo, Taxonomy • Near-infrared spectroscopic observations of potentially-hazardous asteroid (PHA) 2004 XP 14 were remotely obtained on July 5, 2006, using the Spe. X instrument at NASA IRTF as a Target of Opportunity. • Given its heliocentric distance (1. 02 A. U. ) at the time of observation, a sharp rise in reflectance beyond 2. 0 -µm due to thermal emission would be expected if the PHA was a low albedo object. No such excess was detected in the spectrum of 2004 XP 14 which establishes a lower limit on the albedo. • Using Standard Thermal Model and methods developed by Abell (2003), we estimate the lower limit on the albedo to be 20%. • A high albedo (>20%) featureless spectrum suggests that 2004 XP 14 belongs to the M- or E-type taxonomic class.

Diameter NIR Spectrum of 2004 XP 14 • We estimate the diameter of 2004 XP 14 (assuming G = 0. 42, H = ~19. 90) to be ~300± 20 meters. • Radar derived diameter reported by Benner et al. , in Nature ~260 meters. The IRTF was able to respond quickly to take advantage the short window of opportunity (a few days) in order to observe this PHA. This emphasizes both the flexibility of the system and the ability of observers to obtain such short notice observations from their home institutions.

Publications • Reddy, V. , Gaffey, M. J. , Hardersen, P. S. , Abell, P. A. , Kumar, S. , 2006. Constraining Albedo and Composition of Potentially. Hazardous Asteroids 2004 XP 14 and (100085) 1992 UY 4 via Near. IR Spectroscopy. American Astronomical Society, DPS meeting #38. • Reddy, V. , Gaffey, M. J. , Abell, P. A. , Hardersen, P. S. , Kumar, S. , Constraining Albedo, Diameter, Composition of Potentially. Hazardous Asteroids. (In Preparation)