122 Gerda

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122 Gerda
Discovery
Discovered by Christian Heinrich Friedrich Peters
Discovery date July 31, 1872
Designations
 
Minor planet category Main belt
Orbital characteristics[1]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion 501.593 Gm (3.353 AU)
Perihelion 462.356 Gm (3.091 AU)
481.975 Gm (3.222 AU)
Eccentricity 0.041
2112.255 d (5.78 a)
16.59 km/s
283.072°
Inclination 1.639°
178.433°
325.878°
Physical characteristics
Dimensions 81.7 km
Mass 5.7×1017 kg
0.0228 m/s²
0.0432 km/s
10.687 ± 0.001[2] h
Temperature ~155 K
Spectral type
S
7.87

122 Gerda is a fairly large outer main-belt asteroid that was discovered by German-American astronomer C. H. F. Peters on July 31, 1872, and named after Gerðr, the wife of the god Freyr in Norse mythology. Based upon its spectrum, this is classified as an S-type asteroid. It is listed as a member of the Hecuba group of asteroids that orbit near the 2:1 mean-motion resonance with Jupiter.[3]

Photometric observations of this asteroid in 2007 were used to produce a light curve that showed that Gerda rotates every 10.687 ± 0.001 hours and varied in brightness by 0.16 in magnitude.[2] In 2009, observations at the Organ Mesa Observatory in Las Cruces, New Mexico generated a light curve with a period of 10.712 ± 0.01 hours with a brightness variation of 0.11 ± 0.01 magnitudes. This is compatible with previous studies.[4]

See also[edit]

References[edit]

  1. ^ Yeomans, Donald K., "122 Gerda", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-03-25. 
  2. ^ a b Buchheim, Robert K. (March 2007), "Lightcurves for 122 Gerda, 217 Eudora, 631 Phillipina 670 Ottegebe, and 972 Cohnia", Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers 34 (1): 13–14, Bibcode:2007MPBu...34...13B. 
  3. ^ McDonald, Sophia Levy (June 1948), "General perturbations and mean elements, with representations of 35 minor planets of the Hecuba group", Astronomical Journal 53: 199, Bibcode:1948AJ.....53..199M, doi:10.1086/106097. 
  4. ^ Pilcher, Frederick (October 2009), "New Lightcurves of 8 Flora, 13 Egeria, 14 Irene, 25 Phocaea 40 Harmonia, 74 Galatea, and 122 Gerda", Bulletin of the Minor Planets Section of the Association of Lunar and Planetary Observers 36 (4): 133–136, Bibcode:2009MPBu...36..133P.