Long-slit CCD spectroscopy of planetary radar targets 1999 AP10, 2000 TO64, and 2000 UJ1

ATel #2283; Michael Hicks (JPL/Caltech), Stephen Lowry (University of Kent), Paul Weissman (JPL/Caltech)
on 5 Nov 2009; 18:57 UT
Credential Certification: Michael D. Hicks (Michael.Hicks@jpl.nasa.gov)

Tweet

We report taxonomic classifications of three near-Earth asteroids (1999 AP10, 2000 TO64, and 2000 UJ1) scheduled for radar observation at the Arecibo facility during Oct-Nov 2009, using long-slit CCD spectroscopy acquired at the Palomar 5-m telescope on 2009 Oct 19 UT. Table 1 lists the observational circumstances. A comparison of our normalized reflectance spectra with the 1341 asteroid spectra archived in the SMASS II database (Bus & Binzel 2002) was used to determine taxonomy and we found 1999 AP10, 2000 TO64, and 2000 UJ1 to most likely belong to Sa, Sk, and Xk spectral classes, respectively, as shown in Figures 1-3 [1][2][3]. Table 2 lists the five best SMASS II spectral analogs for each of our targets. Additional optical spectroscopy and near-IR spectroscopy over the coming weeks would be extremely useful to help constrain each object's surface composition.

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:  Observational Circumstances.  
  
Object Name   r (AU)  delta (AU)  p (deg)  V (mag)  Exp Time (min)  
1999 AP10     1.034     0.076      58.9     12.6         5.5  
2000 TO64     1.089     0.307      64.4     16.7        35.0  
2000 UJ1      1.062     0.301      69.3     17.6        45.0  

  
Table 2:  Best-fit SMASS II spectral analogs.  
  
                          TAXONOMIC CLASS  
MISFIT  OBJECT NAME        (THOLEN) (BUS)  
  
    - for 1999 AP10 -  
0.695 625 Xenia                       Sa  
0.789 189 Phthia              S       Sa  
0.804 2733 Hamina                     Ld  
0.898 5840 1978 ON                    Ld  
0.905 898 Hildegard                   Sl  
  
    - for 2000 TO64 -  
0.923 3674 Erbisbuhl          (S)     Sk  
0.941 6847 Kunz-Hallstein             Sk  
0.973 2078 Nanking            (S)     Sq  
0.978 534 Nassovia            S       Sq  
1.003 2089 Cetacea            S       Sq  
  
    - for 2000 UJ1 -  
2.158 135 Hertha              M       Xk  
2.178 559 Nanon               C       Xk  
2.220 4424 Arkhipova                  Xk  
2.239 71 Niobe                S       Xe  
2.260 186 Celuta              S       K