107 Camilla

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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)[change | change source]

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
Category Main belt (Cybele)
Longest distance from the center of its orbital path
("semi-major axis")
1235 ± 16 km
How long it takes to complete an orbit 3.710 ± 0.001 d
Average speed 24.2 m/s
Angle above the reference plane
< 10°
What it orbits 107 Camilla
Size and other qualities
Measurements ~ 11 ± 2 km[4]
Mass ~1.5×1015 kg[5]
Escape velocity ~ 6 m/s
True brightness
("absolute magnitude")
107 Camilla
Discovered by Norman Robert Pogson
Discovery date November 17, 1868
Other names A893 QA; 1938 OG; 1949 HD1
Category Main belt (Cybele)
Reference date December 31, 2006 (JD 2454100.5)
Longest distance from the Sun 560.937 Gm (3.750 AU)
Shortest distance from the Sun 479.343 Gm (3.204 AU)
Longest distance from the center of its orbital path
("semi-major axis")
520.140 Gm (3.477 AU)
How long it takes to complete an orbit 2368.050 d (6.48 a)
Average speed 15.95 km/s
Mean anomaly 1.746°
Angle above the reference plane
Size and other qualities
Measurements 285×205×170 ± 20 km[1][4][6][7]
Mass 1.09±0.04×1019 kg[3][8]
Average density ~1.9 g/cm³[3]
Surface gravity ~0.036 m/s²
Escape velocity 0.10 km/s
Rotation period 0.2018 d (4.84393 h)[1]
How much light it reflects 0.0525[6]
Avg. surface temp. ~151 K
max: 223 K (-52°C)
Spectral type C[9]
True brightness
("absolute magnitude")

References[change | change source]

  1. 1.0 1.1 1.2 J. Torppa et al. (2003). "Shapes and rotational properties of thirty asteroids from photometric data". Icarus 164: 346. http://www.rni.helsinki.fi/~mjk/thirty.pdf.
  2. 2.0 2.1 2.2 IAUC 7599[dead link]
  3. 3.0 3.1 3.2 3.3 3.4 107 Camilla and S/2001 (107) 1, F. Marchis Archived 16 January 2010 at WebCite
  4. 4.0 4.1 4.2 4.3 F. Marchis et al. (2006). "Shape, size and multiplicity of main-belt asteroids I. Keck Adaptive Optics survey". Icarus 185: 39. 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. 6.0 6.1 6.2 Supplemental IRAS Minor Planet Survey Archived 17 January 2010 at WebCite
  7. 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).
  8. Error estimate derived from consideration of M \propto a^3/P^2 and given errors in a and P. See propagation of uncertainty.
  9. PDS spectral class data Archived 16 January 2010 at WebCite

Other websites[change | change source]