Palomar Spectroscopy of Near-Earth Asteroids 2004 SV55, 2000 SP43, 3988 (1986 LA), 1036 Ganymed, and 2002 AG29.
ATel #3678; M Hicks (JPL/CalTech), C. Gerhart (LAVC), C. Strojia (VVC), S. Teague (VVC)
on 11 Oct 2011; 21:00 UT
Credential Certification: Michael D. Hicks (Michael.Hicks@jpl.nasa.gov)
Subjects: Optical, Asteroid, Solar System Object, Near-Earth Object, Potentially Hazardous Asteroid
We obtained long-slit CCD spectrograms of the near-Earth asteroids 2004 SV55, 2000 SP43, 3988 (1986 LA), 1036 Ganymed, and 2002 AG29 using the Palomar 5-m Hale Telescope equipped with the facility dual-channel spectrometer on October 04 2011. Several of our objects (2004 SV55, 2000 SP43, 1036 Ganymed, 2002 AG29) have been scheduled for observation at thermal wavelengths at the IRTF and for radar observation at the Arcibo/Goldstone Facilities. 2000 SP43 and 1986 LA have been designated as Potentially Hazardous Asteroids by the Minor Planets Center, although they currently pose no significant impact threat.
Table 1 summarizes our observational circumstances, using the orbital elements and absolute magnitude H_V maintained by the JPL HORIZONS database. Table 2 lists the solar analog stars used to generate the composite normalized reflectance spectra shown in Figures 1-5
[1][2][3][4][5]. All observations were obtained through variable cirrus.
A comparison of our optical spectra with the 1341 asteroid spectra archived in the SMASS II database (Bus & Binzel 2002) was used to determine taxonomy. Table 3 list the four best-fit SMASS II analogs for each object. We identify 2004 SV55, 2000 SP43, 3988 (1986 LA), 1036 Ganymed, and 2002 AG29 as Xe, Sr, Sl, S, and S-type asteroids, respectively. Both 1986 LA and 2002 AG29 remain well-placed for lightcurve study from the northern hemisphere through November 2011 and collaborative observations with other researchers would be very welcomed.
Copyright 2011. 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. The student participation was supported by the National Science Foundation under REU grant 0852088 to Cal State LA.
Table 1: Observational Circumstances.
Object Name r (AU) delta (AU) phase (deg) H (mag) V (mag) Exp Time (min)
2004 SV55 1.085 0.314 66.1 17.9 17.9 40.0
2000 SP43 1.121 0.148 33.4 18.5 16.0 50.0
1986 LA 1.192 0.244 34.4 18.2 17.0 35.0
1036 Ganymed 1.293 0.369 33.3 9.5 9.0 0.5
2002 AG29 1.157 0.200 35.1 18.2 16.5 15.0
Table 2: Solar Analog Stars.
Object Name Solar Analog Stars
2004 SV55 16 Cyg B
2000 SP43 113-276, 92-276
1986 LA 113-276
1036 Ganymed 113-276
2002 AG29 113-276, 92-276
Table 3: Best-fit SMASS II spectral analogs.
TAXONOMIC CLASS
MISFIT OBJECT NAME (THOLEN) (BUS)
- for 2004 SV55 -
1.677 64 Angelina E Xe
1.701 135 Hertha M Xk
1.716 559 Nanon C Xk
1.720 71 Niobe S Xe
- for 2000 SP43 -
0.726 5051 Ralph Sr
0.735 7564 1988 CA S
0.748 3792 Preston (S) S
0.780 862 Franzia S
- for 1986 LA -
1.042 897 Lysistrata S Sl
1.146 10504 Doga Sl
1.147 3349 Manas L
1.168 4718 Araki Sl
- for 1036 Ganymed -
0.350 174 Phaedra S S
0.353 5732 1988 WC S
0.362 5685 Sanenobufukui S
0.407 384 Burdigala S S
- for 2002 AG29 -
1.344 4479 Charlieparker S
1.387 4299 WIYN S
1.389 2167 Erin S
1.420 6192 1990 KB1 S