Discovered by Alphonse Borrelly Pronunciation /ˈlækᵻsɪs/ Observation arc 143.70 yr (52485 d) Discovered 10 April 1872 Spectral type C-type asteroid Named after Lachesis | Discovery date 10 April 1872 Minor planet category Main belt Aphelion 3.2814 AU (490.89 Gm) Orbits Sun Discoverer Alphonse Borrelly Discovery site Marseille Observatory | |
Similar 121 Hermione, 128 Nemesis, 76 Freia, 97 Klotho, 165 Loreley | ||
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. A Lachesean occultation of a star occurred in 1999 and was confirmed visually by five observers and once photoelectrically.
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. It has the longest rotation period of an asteroid more than 150 km in diameter. As a primitive C-type asteroid it is probably composed of carbonaceous material.