Astronomy:123 Brunhild

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Short description: Main-belt asteroid
123 Brunhild
Discovery
Discovered byChristian Heinrich Friedrich Peters
Discovery date31 July 1872
Designations
(123) Brunhild
Pronunciation/ˈbrnhɪld/[1]
Named afterBrynhildr
A872 OB
Minor planet categoryMain belt
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc143.71 yr (52490 days)
|{{{apsis}}}|helion}}3.0183 astronomical unit|AU (451.53 Gm)
|{{{apsis}}}|helion}}2.37594 AU (355.436 Gm)
2.69710 AU (403.480 Gm)
Eccentricity0.11907
Orbital period4.43 yr (1617.9 d)
Average Orbital speed18.08 km/s
Mean anomaly96.8286°
Mean motion0° 13m 21.054s / day
Inclination6.4142°
Longitude of ascending node307.834°
125.960°
Earth MOID1.39621 AU (208.870 Gm)
Jupiter MOID2.22588 AU (332.987 Gm)
TJupiter3.350
Physical characteristics
Dimensions48 km[2]
Mean radius23.985±1.3 km
Mass1.2×1017 kg (assumed)
Equatorial surface gravity
0.0134 m/s2
Equatorial escape velocity
0.0254 km/s
Rotation period10.04 h (0.418 d)[2]
Geometric albedo0.2134±0.026[2]
Physics~170 K
S[2]
Apparent magnitude11.77 to 14.88
Absolute magnitude (H)8.9[2]


Brunhild (minor planet designation: 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.[3]

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.[4]

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.[2] 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.[5]

References

  1. Benjamin Smith (1903) The Century Dictionary and Cyclopedia
  2. 2.0 2.1 2.2 2.3 2.4 2.5 2.6 Yeomans, Donald K., "123 Brunhild", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=123, retrieved 30 April 2016. 
  3. "The International Variable Star Index: KN Gem". American Association of Variable Star Observers (AAVSO). http://www.aavso.org/vsx/index.php?view=detail.top&oid=14541. Retrieved 2011-12-31. 
  4. 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, Bibcode1984A&AS...57..103B. 
  5. Tedesco, Edward F. et al. (July 2002), "The Midcourse Space Experiment Infrared Minor Planet Survey", The Astronomical Journal 124 (124): 583–591, doi:10.1086/340960, Bibcode2002AJ....124..583T. 

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