107 Camilla

107 Camilla (pronounced /kəˈmɪlə/ kə-MIL-ə) is one of the largest main belt asteroids. It orbits within the Cybele Group, beyond most of the main belt asteroids. It has a very dark surface and primitive carbonaceous composition. It was discovered by N. R. Pogson on November 17, 1868 and named after Camilla, Queen of the Volsci in Roman mythology.

Lightcurve analysis indicates that Camilla's pole most likely points towards ecliptic coordinates (β, λ) = (+51°, 72°) with a 10° uncertainty [1], which gives it an axial tilt of 29°.

Satellite (S/2001 (107) I)

On 1 March 2001, a satellite of Camilla was found by A. Storrs, F. Vilas, R. Landis, E. Wells, C. Woods, B. Zellner, and M. Gaffey using the Hubble Space Telescope [2]. It has been designated S/2001 (107) 1 but has not yet received an official name.

Later observations in September 2005 with the VLT allowed the determination of an orbit [3]. Apart from data in infobox, the inclination was found to be 3 ± 1° with respect to an axis pointing towards (β, λ) = (+55°, 75°) [3]. Given the ~10° uncertainty in the actual rotational axis of Camilla, one can say that the orbit's inclination is less than 10°.

The satellite is estimated to measure about 11 km in diameter [4]. Assuming a similar density to the primary, this would give it an approximate mass of ~1.5 × 1015 kg. It has a similar colour to the primary [2].

External links

* Data on (87) Sylvia from Johnston's archive (maintained by W. R. Johnston)
* Hubble Finds New Asteroid Moon (SpaceDaily.com, 21-03-2001), includes discovery image.
* 107 Camilla and S/2001 (107) 1, orbit data website maintained by F. Marchis. Includes orbit diagrams.

References

1. ^ a b c J. Torppa et al. (2003). "Shapes and rotational properties of thirty asteroids from photometric data" (PDF). Icarus 164: 346. doi:10.1016/S0019-1035(03)00146-5. http://www.rni.helsinki.fi/~mjk/thirty.pdf.
2. ^ a b c IAUC 7599
3. ^ a b c d e 107 Camilla and S/2001 (107) 1, F. Marchis
4. ^ a b c d F. Marchis et al. (2006). "Shape, size and multiplicity of main-belt asteroids I. Keck Adaptive Optics survey". Icarus 185 (1): 39. doi:10.1016/j.icarus.2006.06.001. PMID 19081813. PMC 2600456. http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=2006Icar..185...39M&db_key=AST&data_type=HTML&format=&high=444b66a47d05620.
5. ^ Assuming a similar density to the primary.
6. ^ a b c Jim Baer (2008). "Recent Asteroid Mass Determinations". Personal Website. http://home.earthlink.net/~jimbaer1/astmass.txt. Retrieved 2008-12-05.
7. ^ a b c Supplemental IRAS Minor Planet Survey
8. ^ Axis ratios (rounded to nearest 5 km) based on lightcurve analysis of Torppa et al. (2003), however taking IRAS mean diameter is inconsistent with the maximum value of the short axis obtained in Marchis et al. (2006). Hence, presumably IRAS measurements were taken of a large face. Therefore, anchoring absolute size by requiring the shortest axis to be no larger than the maximum allowed by Marchis et al. (2006).
9. ^ Error estimate derived from consideration of M proportional to a³/P² and given errors in a and P. See propagation of uncertainty.
10. ^ PDS spectral class data
11. ^ "AstDys (107) Camilla Ephemerides". Department of Mathematics, University of Pisa, Italy. Retrieved 2010-06-28.