Spitzer observations of the asteroid-comet transition object and potential spacecraft target 107P (4015) Wilson-Harrington

    Authors

    J. Licandro; H. Campins; M. Kelley; Y. Fernandez; M. Delbo; W. T. Reach; O. Groussin; P. L. Lamy; I. Toth; M. F. A'Hearn; J. M. Bauer; S. C. Lowry; A. Fitzsimmons; C. M. Lisse; K. J. Meech; J. Pittichova; C. Snodgrass;H. A. Weaver

    Abbreviated Journal Title

    Astron. Astrophys.

    Keywords

    comets: individual: 107P (4015) Wilson-Harrington; minor planets, ; asteroids; infrared: solar system; NEAR-EARTH ASTEROIDS; THERMAL-PROPERTIES; 3200 PHAETHON; POPULATION; MAGNITUDE; MODEL; Astronomy & Astrophysics

    Abstract

    Context. Near-Earth asteroid-comet transition object 107P/(4015) Wilson-Harrington is a possible target of the joint European Space Agency (ESA) and Japanese Aerospace Exploration Agency (JAXA) Marco Polo sample return mission. Physical studies of this object are relevant to this mission, and also to understanding its asteroidal or cometary nature. Aims. Our aim is to obtain significant new constraints on the surface thermal properties of this object. Methods. We present mid-infrared photometry in two filters (16 and 22 mu m) obtained with NASA's Spitzer Space Telescope on February 12, 2007, and results from the application of the Near Earth Asteroid Thermal Model (NEATM). We obtained high S/N in two mid-IR bands allowing accurate measurements of its thermal emission. Results. We obtain a well constrained beaming parameter (eta = 1.39 +/- 0.26) and obtain a diameter and geometric albedo of D = 3.46 +/- 0.32 km, and p(v) = 0.059 +/- 0.011. We also obtain similar results when we apply this best-fitting thermal model to single-band mid-IR photometry reported by Campins et al. (1995, P&SS, 43, 733), Kraemer et al. (2005, AJ, 130, 2363) and Reach et al. ( 2007, Icarus, 191, 298). Conclusions. The albedo of 4015 Wilson-Harrington is low, consistent with those of comet nuclei and primitive C-, P-, D-type asteorids. We establish a rough lower limit for the thermal inertia of W-H of 60 Jm(-2)s(-0.5)K(-1) when it is at r = 1 AU, which is slightly over the limit of 30 Jm(-2)s(-0.5)K(-1) derived by Groussin et al. (2009, Icarus, 199, 568) for the thermal inertia of the nucleus of comet 22P/Kopff.

    Journal Title

    Astronomy & Astrophysics

    Volume

    507

    Issue/Number

    3

    Publication Date

    1-1-2009

    Document Type

    Article

    Language

    English

    First Page

    1667

    Last Page

    1670

    WOS Identifier

    WOS:000272180800045

    ISSN

    0004-6361

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