118 Peitho

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118 Peitho
Discovery
Discovered by Karl Theodor Robert Luther
Discovery date March 15, 1872
Designations
Named after Peitho
Minor planet category Main belt
Orbital characteristics[1]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion 424.156 Gm (2.835 AU)
Perihelion 304.927 Gm (2.038 AU)
Semi-major axis 364.541 Gm (2.437 AU)
Eccentricity 0.164
Orbital period 1389.411 d (3.80 a)
Average orbital speed 18.95 km/s
Mean anomaly 224.181°
Inclination 7.743°
Longitude of ascending node 47.743°
Argument of perihelion 33.655°
Physical characteristics
Dimensions 41.7 km
Mass 7.6×1016 kg
Equatorial surface gravity 0.0117 m/s²
Escape velocity 0.0220 km/s
Rotation period 7.823[2] h
Temperature ~178 K
Spectral type S
Absolute magnitude (H) 9.14

118 Peitho is a main-belt asteroid. It is probably an S-type asteroid. It was discovered by R. Luther on March 15, 1872, and named after one of the two Peithos in Greek mythology. There have been two observed Peithoan occultations of a dim star: one was in 2000 and the other in 2003.[3][4]

In 2009, Photometric observations of this asteroid were made at the Palmer Divide Observatory in Colorado Springs, Colorado. The resulting asymmetrical light curve shows a synodic rotation period of 7.823 ± 0.002 hours with a brightness variation of 0.15 ± 0.02 in magnitude. This was reasonably consistent with independent studies performed in 1980 (7.78 hours) and 2009 (7.8033 hours).[2]

References[edit]

  1. ^ Yeomans, Donald K., "118 Peitho", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-03-25. 
  2. ^ a b Warner, Brian D. (October 2009), "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2009 March-June", Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers 36 (4): 172-176, Bibcode:2009MPBu...36..172W, doi:10.1016/j.pss.2012.03.009. 
  3. ^ von Boinik, I. F. B. "Planet (118) Peitho". Astronomische Nachrichten. Volume 145,: 31. 
  4. ^ NASA Planetary Data System