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ID 34749
file
creator
Kim, Junhan
Ishiguro, Masateru
Hanayama, Hidekazu
Hasegawa, Sunao
Usui, Fumihiko
Yanagisawa, Kenshi
Sarugaku, Yuki
Watanabe, Jun-ichi
subject
comets: general
comets: individual (P/2010 A2)
minor planets, asteroids: general
NDC
Astronomy. Space sciences
abstract
An inner main-belt asteroid, P/2010 A2, was discovered on 2010 January 6. Based on its orbital elements, it is considered that the asteroid belongs to the Flora collisional family, where S-type asteroids are common, while showing a comet-like dust tail. Although analysis of images taken by the Hubble Space Telescope and Rosetta spacecraft suggested that the dust tail resulted from a recent head-on collision between asteroids, an alternative idea of ice sublimation was suggested based on the morphological fitting of ground-based images. Here, we report a multiband observation of P/2010 A2 made on 2010 January with a 105 cm telescope at the Ishigakijima Astronomical Observatory. Three broadband filters, g', R-c, and I-c, were employed for the observation. The unique multiband data reveal that the reflectance spectrum of the P/2010 A2 dust tail resembles that of an Sq-type asteroid or that of ordinary chondrites rather than that of an S-type asteroid. Due to the large error of the measurement, the reflectance spectrum also resembles the spectra of C-type asteroids, even though C-type asteroids are uncommon in the Flora family. The reflectances relative to the g' band (470 nm) are 1.096 +/- 0.046 at the R-c band (650 nm) and 1.131 +/- 0.061 at the I-c band (800 nm). We hypothesize that the parent body of P/2010 A2 was originally S-type but was then shattered upon collision into scattering fresh chondritic particles from the interior, thus forming the dust tail.
journal title
Astrophysical Journal Letters
volume
Volume 746
issue
Issue 1
start page
L11
date of issued
2012
publisher
IOP Publishing Ltd
issn
2041-8205
ncid
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
publisher
rights
(c) 2012. The American Astronomical Society. All rights reserved. Printed in the U.S.A.
relation url
department
Hiroshima Astrophysical Science Center