Low Perihelion Near-Earth Asteroids

Campins, Humberto; Fernández, Y.; Kelley, M. S.; Licandro, J.; Hargrove, K.; de León, J.; Pinilla-Alonso, N.; Morbidelli, A.
Referencia bibliográfica

American Astronomical Society, DPS meeting #40, #28.19; Bulletin of the American Astronomical Society, Vol. 40, p.439

Fecha de publicación:
9
2008
Número de autores
8
Número de autores del IAC
3
Número de citas
0
Número de citas referidas
0
Descripción
This is a progress report on a project to characterize the surface composition (and other properties such as radius, albedo and thermal inertia) of a sample of low perihelion Near-Earth Asteroids (NEAs), using spec-troscopy in the 0.3 to 2.5 micron region (groundbased) and in the 7 to 14 micron region (Spitzer). NEAs with low perihelion distances represent a unique laboratory in which to study the effects of thermal processing on asteroid surfaces. We will study the mineral and or-ganic composition of our targets and we will search for correlations between their spectral characteristics and other properties such as size, albedo, rotational and orbital properties. Understanding how asteroid surfaces change as a result of exposure to high temperatures will help constrain models of the compositional and thermal environment in the region of the protoplanetary disk where asteroids formed. Part of the motivation to study these low perihelion NEAs comes from the results of our recent study of 3200 Phaethon [1], where we found indications that the surface mineralogy of this low perihelion NEA may have been altered by the perihe-lion thermal pulse. More specifically, the only two me-teorite samples that showed approximately the same spectral shape (in the visible and near-infrared) as Phaethon, had been heated. One is a sample of the CI meteorite Ivuna heated in the laboratory to about 1000 K, and the other a sample of the unusual CI/CM mete-orite Yamato-86720 that seems to have been naturally heated to about 800-900 K. These initial results sug-gests that other low perihelion NEAs may also show the effects of thermal processing on their surfaces. PROGRESS: Spitzer observations of our 25 targets started in 2007 and groundbased spectroscopy started at the Telescopio Nazionale Galileo (TNG) in July 2008. Reference: Licandro, J. et al. (2007) Astron. & Astrophys., 461, 751.