# 107 Camilla

107 Camilla is one of the biggest main belt asteroids. It orbits within the Cybele Group, beyond most of the main belt asteroids. It has a very dark surface and is made of carbonate. It was found by N. R. Pogson on November 17, 1868, and named after Camilla, Queen of the Volsci in Roman mythology.

Study of its light curve shows that Camilla's pole probably points towards ecliptic coordinates (β, λ) = (+51°, 72°) with a 10° uncertainty,[1] which gives it an axial tilt of 29°.

## Moon (S/2001 (107) I)

On March 1, 2001, a moon 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 labelled S/2001 (107) 1 but it does not yet have an official name.

Later sightings in September 2005 with the VLT allowed scientists to work out its 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, the orbit's inclination probably is less than 10°.

The moon is estimated to be about 11 km in diameter.[4] If it has the same density as Camilla, this would give it a mass of about ~1.5×1015 kg. It has a similar colour to Camilla.[2]

S/2001 (107) 1
Discovery[2] and designation
Discovered by A. Storrs, F. Vilas,
R. Landis, E. Wells,
C. Woods, B. Zellner,
and M. Gaffey
Discovery date 1 March 2001
Designations
Minor planet category Main belt (Cybele)
Orbital characteristics[3]
Semi-major axis 1235 ± 16 km
Eccentricity 0.006 ± 0.002
Orbital period 3.710 ± 0.001 d
Average orbital speed 24.2 m/s
Inclination < 10°
Satellite of 107 Camilla
Physical characteristics
Dimensions ~ 11 ± 2 km[4]
Mass ~1.5×1015 kg[5]
Equatorial escape velocity ~ 6 m/s
107 Camilla
Discovery
Discovered by Norman Robert Pogson
Discovery date November 17, 1868
Designations
Alternative names A893 QA; 1938 OG; 1949 HD1
Minor planet category Main belt (Cybele)
Orbital characteristics
Epoch December 31, 2006 (JD 2454100.5)
Aphelion 560.937 Gm (3.750 AU)
Perihelion 479.343 Gm (3.204 AU)
Semi-major axis 520.140 Gm (3.477 AU)
Eccentricity 0.078
Orbital period 2368.050 d (6.48 a)
Average orbital speed 15.95 km/s
Mean anomaly 1.746°
Inclination 10.048°
Longitude of ascending node 173.132°
Argument of perihelion 309.877°
Physical characteristics
Dimensions 285×205×170 ± 20 km[1][4][6][7]
Mass 1.09±0.04×1019 kg[3][8]
Mean density ~1.9 g/cm³[3]
Equatorial surface gravity ~0.036 m/s²
Escape velocity 0.10 km/s
Rotation period 0.2018 d (4.84393 h)[1]

## References

1. J. Torppa et al. (2003). "Shapes and rotational properties of thirty asteroids from photometric data". Icarus 164: 346.
2. 107 Camilla and S/2001 (107) 1, F. Marchis Archived 16 January 2010 at WebCite
3. Assuming a similar density to the primary.
4. Supplemental IRAS Minor Planet Survey Archived 17 January 2010 at WebCite
5. 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 reuqiring the shortest axis to be no larger than the maximum allowed by Marchis et al. (2006).
6. Error estimate derived from consideration of $M \propto a^3/P^2$ and given errors in a and P. See propagation of uncertainty.
7. PDS spectral class data Archived 16 January 2010 at WebCite