123 Brunhild

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123 Brunhild
Discovery
Discovered by Christian Heinrich Friedrich Peters
Discovery date July 31, 1872
Designations
Named after Brynhildr
Minor planet category Main belt
Orbital characteristics[1]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion 452.102 Gm (3.022 AU)
Perihelion 353.956 Gm (2.366 AU)
Semi-major axis 403.029 Gm (2.694 AU)
Eccentricity 0.122
Orbital period 1615.156 d (4.42 a)
Average orbital speed 18.08 km/s
Mean anomaly 38.416°
Inclination 6.428°
Longitude of ascending node 307.954°
Argument of perihelion 124.933°
Physical characteristics
Dimensions 48[1] km
Mass 1.2×1017 kg (assumed)
Equatorial surface gravity 0.0134 m/s²
Escape velocity 0.0254 km/s
Rotation period 10.04 hr[1]
Albedo 0.2134[1]
Temperature ~170 K
Spectral type S[1]
Apparent magnitude 11.77 to 14.88
Absolute magnitude (H) 8.89[1]

123 Brunhild is a stony S-type main-belt asteroid. It was discovered by German-American astronomer C. H. F. Peters on July 31, 1872, and named after Brünnehilde, a Valkyrie in Norse mythology. Brunhild has been mistaken for the non-existent variable star KN Gem.[2]

In 1983, 123 Brunhild was observed photometrically from the Observatoire de Haute-Provence, producing an irregular light curve that showed eight extremes, including two minima and two maxima that were more accentuated than the others. This curve indicates an irregular shape or possibly areas with higher albedo, with a rotation period of 10.04 ± 0.02 hours and a brightness variation of 0.16 ± 0.01 in magnitude.[3]

Based upon IRAS observations, the estimated diameter of this asteroid is 47.97 ± 2.6 km with a geometric albedo of 0.2134 ± 0.026.[1] A smaller diameter value of 41.33 ± 1.73 km is obtained from the Midcourse Space Experiment observations, with an accordingly higher albedo of 0.2886 ± 0.0247.[4]

References[edit]

  1. ^ a b c d e f g Yeomans, Donald K., "123 Brunhild", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-03-25. 
  2. ^ "The International Variable Star Index: KN Gem". American Association of Variable Star Observers (AAVSO). Retrieved 2011-12-31. 
  3. ^ Barucci, M. A.; di Martino, M. (July 1984), "Rotational rates of very small asteroids - 123 Brunhild, 376 Geometria, 437 Rhodia and 1224 Fantasia", Astronomy and Astrophysics Supplement Series 57: 103-106, Bibcode:1984A&AS...57..103B. 
  4. ^ Tedesco, Edward F. et al. (July 2002), "The Midcourse Space Experiment Infrared Minor Planet Survey", The Astronomical Journal 124 (124): 583-591, Bibcode:2002AJ....124..583T, doi:10.1086/340960. 

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