120 Lachesis

120 Lachesis
3D convex shape model of 120 Lachesis
Discovery
Discovered byAlphonse Borrelly
Discovery date10 April 1872
Designations
(120) Lachesis
Pronunciation/ˈlækɪsɪs/ LAK-iss-iss[1]
Named after
Lachesis
A872 GB; 1910 CF;
1918 UB
Main belt
AdjectivesLachesian (/læˈkiːʃ(i)ən, ləˈkiːʒən/ la-KEE-sh(ee-)ən, lə-KEE-zhən)
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc143.70 yr (52485 d)
Aphelion3.2814 AU (490.89 Gm)
Perihelion2.95390 AU (441.897 Gm)
3.11767 AU (466.397 Gm)
Eccentricity0.052528
5.50 yr (2010.7 d)
16.86 km/s
56.2095°
0° 10m 44.558s / day
Inclination6.9643°
341.193°
232.822°
Earth MOID1.95464 AU (292.410 Gm)
Jupiter MOID1.72275 AU (257.720 Gm)
TJupiter3.204
Physical characteristics
Dimensions155.132±1.133 km (IRAS)[2]
Mass5.5×1018 kg
Equatorial surface gravity
0.0487 m/s2
Equatorial escape velocity
0.0920 km/s
46.551 h (1.9396 d)[2][3]
0.0463±0.002[2]
Temperature~158 K
C[4]
7.75[2]

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.[5] A Lachesean occultation of a star occurred in 1999 and was confirmed visually by five observers and once photoelectrically, with the chords yielding an estimated elliptical cross-section of 184 × 144 km.[6]

This body is orbiting the Sun with a period of 5.50 years and an eccentricity (ovalness) of 0.05. The orbital plane is inclined by 7° to the plane of the ecliptic. 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.[3] It is a very slow rotator[7] with the longest rotation period of an asteroid more than 150 km in diameter.[8] As a primitive C-type asteroid[4] it is probably composed of carbonaceous material.

  1. ^ "Lachesis". Lexico UK English Dictionary. Oxford University Press. Archived from the original on March 23, 2020.
  2. ^ a b c d e Cite error: The named reference jpldata was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Pilcher2009 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Tedesco1989 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference Schmadel2003 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference Dunham2002 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Bembrick2005 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference SBDB was invoked but never defined (see the help page).