103 Hera

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103 Hera
Discovery
Discovered by James Craig Watson[1]
Discovery date September 7, 1868[1]
Designations
Named after
Hera
1927 CV, 1950 CM
Minor planet category Main belt
Orbital characteristics[2]
Epoch August 27, 2011 (JD 2455800.5)[1]
Aphelion 437.17 Gm (2.9223 AU)[1]
Perihelion 371.24 Gm (2.4816 AU)[1]
404.202 Gm (2.702 AU)[1]
Eccentricity 0.0815455[1]
1622.213 d (4.4414 a)[1]
18.09 km/s
74.835°
Inclination 5.421°
136.276°
190.160°
Physical characteristics
Dimensions 91.2 km
Mass 7.9×1017 kg
0.0255 m/s²
0.0482 km/s
0.9892[3] d
Temperature ~170 K
Spectral type
S[4]
7.66

103 Hera is a moderately large main-belt asteroid that was discovered by Canadian-American astronomer James Craig Watson on September 7, 1868,[5] and named after Hera, queen and fifth in power of the Olympian gods in Greek mythology. It is an S-type asteroid[4] with a silicate surface composition.

Photometric observations made in 2010 at the Organ Mesa Observatory at Las Cruces, New Mexico, and the Hunters Hill Observatory at Ngunnawal, Australian Capital Territory, give a synodic rotation period of 23.740 ± 0.001 hours. The bimodal light curve shows a maximum brightness variation of 0.45 ± 0.03 in magnitude.[3]

Measurements made with the IRAS observatory give a diameter of 91.58 ± 4.14 km and a geometric albedo of 0.19 ± 0.02. By comparison, the MIPS photometer on the Spitzer Space Telescope gives a diameter of 88.30 ± 8.51 km and a geometric albedo of 0.20 ± 0.04. When the asteroid was observed occulting a star, the results showed a diameter of 89.1 ± 1.1 km.[6]

References[edit]

  1. ^ a b c d e f g h JPL Small-Body Database Browser
  2. ^ Yeomans, Donald K., "103 Hera", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-03-25. 
  3. ^ a b Pilcher, Frederick (January 2011), "Rotation Period Determination for 103 Hera", Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers 38 (1): 32, Bibcode:2011MPBu...38...32P. 
  4. ^ a b DeMeo, Francesca E. et al. (2011), "An extension of the Bus asteroid taxonomy into the near-infrared", Icarus 202 (1): 160–180, Bibcode:2009Icar..202..160D, doi:10.1016/j.icarus.2009.02.005, retrieved 2013-03-22.  See appendix A.
  5. ^ "Numbered Minor Planets 1–5000", Discovery Circumstances (IAU Minor Planet center), retrieved 2013-04-07. 
  6. ^ Ryan, Erin Lee et al. (April 2012), "The Kilometer-Sized Main Belt Asteroid Population as Revealed by Spitzer", eprint arXiv, arXiv:1204.1116, Bibcode:2012arXiv1204.1116R.