Broad-band Photometry of the Potentially Hazardous Asteroid 2009 KC3.
ATel #2247; M. Hicks (JPL/Caltech), T. Barajas (LACC), A. McAuley (CSULA)
on 19 Oct 2009; 03:11 UT
Credential Certification: Michael D. Hicks (Michael.Hicks@jpl.nasa.gov)
Subjects: Optical, Asteroid, Planet (minor), Solar System Object
The near-Earth asteroid 2009 KC3 was discovered by the Siding Spring
Survey on May 23 2009 (MPEC 2009-K39). With an Absolute Magnitude H=17.9
and a Minimum Orbit Intersection Distance MOID=0.010 AU, the object has been
designated as a Potentially Hazardous Asteroid (PHA) by the Minor Planet
Center. 2009 KC3 has an orbit similar to many Jupiter-family
comets (Tisserand Invariant T=2.73), implying a possible cometary past.
We obtained Bessel BVRI colors over the course of two partial nights at the
JPL Table Mountain Observatory (TMO) 0.6-m telescope
(Figure 1
and Table 1).
We compared our averaged broad-band colors (B-R=1.130+/-0.027 mag;
V-R=0.388+/-0.014 mag; I-R=0.338+/-0.025 mag) with 1341 asteroid spectra
collected by the
SMASS II survey (Bus & Binzel 2002) and found
the colors best matched by the C-type asteroid 1716 Peter
(Figure 2
and Table 2). However, our colors were also consistent with the Xe-type
asteroids 396 Aeolia and 2001 Einstein. This is problematic for resolving
any possible asteroid-comet connection: C-type asteroids have low
albedos, similar to the primitive surfaces of cometary
nuclei, while Xe asteroids tend to have moderate to high albedos,
consistent with a more evolved mineralogy.
Thermal observations and/or optical/near-IR spectroscopy would be
required to resolve this ambiguity.
Copyright 2009. All rights reserved. The research described in this telegram was
carried out at the Jet Propulsion Laboratory, under a contract with the National
Aeronautics and Space Administration.
Table 1: TMO observational summary.
UT Date |
r (AU) |
delta (AU) |
phase (deg) |
Num. Exp. |
Observers |
Sep 20.46 |
1.11 |
0.18 |
50.4 |
13 |
A. McAuley |
Sep 24.19 |
1.14 |
0.21 |
45.4 |
82 |
T. Barajas |
Table 2: Top 5 spectral matches in the SMASS II database.
Misfit |
Asteroid Name |
Taxonomic Class |
 |
 |
(Tholen) |
(Bus) |
0.159 |
1716 Peter |
 |
C |
0.267 |
1396 Aeolia |
 |
Xe |
0.358 |
2001 Einstein |
X |
Xe |
0.596 |
783 Nora |
 |
C |
0.649 |
1517 Beograd |
 |
X |