120 Lachesis

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120 Lachesis
Discovery
Discovered by Alphonse Borrelly
Discovery date April 10, 1872
Designations
Pronunciation /ˈlækɨsɪs/
Named after
Lachesis
 
Minor planet category Main belt
Orbital characteristics[1]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion 493.828 Gm (3.301 AU)
Perihelion 438.480 Gm (2.931 AU)
466.154 Gm (3.116 AU)
Eccentricity 0.059
2009.115 d (5.50 a)
16.86 km/s
150.174°
Inclination 6.954°
341.511°
232.006°
Physical characteristics
Dimensions 174.1 ±?? km[citation needed]
Mass 5.5×1018 kg
0.0487 m/s²
0.0920 km/s
46.551[2] h
Temperature ~158 K
Spectral type
C[3]
7.75

120 Lachesis is a large main-belt asteroid. It was discovered by French astronomer Alphonse Borrelly on April 10, 1872, and independently by German-American astronomer Christian Heinrich Friedrich Peters on April 11, 1872, then named after Lachesis, one of the Moirai, or Fates, in Greek mythology.[4] A Lachesean occultation of a star occurred in 1999 and was confirmed visually by five observers and once photoelectrically.[5]

Photometric observations of this asteroid were made in early 2009 at the Organ Mesa Observatory in Las Cruces, New Mexico. The resulting light curve shows a synodic rotation period of 46.551 ± 0.002 hours with a brightness variation of 0.14 ± 0.02 in magnitude.[2] As a primitive C-type asteroid[3] it is probably composed of carbonaceous material.

References[edit]

  1. ^ Yeomans, Donald K., "120 Lachesis", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-03-25. 
  2. ^ a b Pilcher, Frederick (July 2009), "Rotation Period Determinations for 120 Lachesis, 131 Vala 157 Dejanira, and 271 Penthesilea", Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers 36 (3): 100-102, Bibcode:2009MPBu...36..100P. 
  3. ^ a b Tedesco, E. F. et al. (February 1989), "A three-parameter asteroid taxonomy", Astronomical Journal 97: 580-606, Bibcode:1989AJ.....97..580T, doi:10.1086/115007. 
  4. ^ Schmadel, Lutz D. (2003), Dictionary of Minor Planet Names 1 (5th ed.), Springer, p. 26, ISBN 3540002383. 
  5. ^ Dunham, D. W. et al. (September 2002), "Asteroidal occultation results multiply helped by Hipparcos", Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers 73 (3): 662, Bibcode:2002MmSAI..73..662D.