2430 Bruce Helin

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2430 Bruce Helin
Discovery [1]
Discovered by E. F. Helin
E. Shoemaker
Discovery site Palomar Obs.
Discovery date 8 November 1977
MPC designation (2430) Bruce Helin
Named after
Bruce Helin
(son of discoverer)[2]
1977 VC · 1976 JU1
A908 WC
main-belt · Phocaea[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 40.44 yr (14,772 days)
Aphelion 2.8697 AU
Perihelion 1.8555 AU
2.3626 AU
Eccentricity 0.2146
3.63 yr (1,326 days)
0° 16m 17.04s / day
Inclination 23.459°
Physical characteristics
Dimensions 11.83±0.17 km[4]
12.10 km (calculated)[3]
12.47±0.32 km[5]
128 h[a]
129.4163±0.3970 h[6]
129.75 h[7]
0.23 (assumed)[3]
B–V = 0.815[1]
U–B = 0.415[1]
S (Tholen)[1] · Sl (SMASS)[1] · S[3]
11.8[1][3] · 12.24[4] · 11.70[5] · 11.78±0.48[8] · 11.693±0.003 (R)[6]

2430 Bruce Helin, provisional designation 1977 VC, is a stony Phocaea asteroid and slow rotator from the inner regions of the asteroid belt, approximately 12 kilometers in diameter.

It was discovered by American astronomers Eleanor Helin and Eugene Shoemaker at the U.S. Palomar Observatory in California, on 8 November 1977.[9] It was later named after Bruce Helin, son of the first discoverer.[2]

Orbit and classification[edit]

Bruce Helin is a member of the Phocaea family. It orbits the Sun in the inner main-belt at a distance of 1.9–2.9 AU once every 3 years and 8 months (1,326 days). Its orbit has an eccentricity of 0.21 and an inclination of 23° with respect to the ecliptic.[1] It was first observed at A908 WC at Heidelberg Observatory in 1908. The body's observation arc begins with a precovery taken at Crimea–Nauchnij in 1976, or one year prior to its official discovery observation at Palomar.[9]

Physical characteristics[edit]

The stony S-type asteroid is classified as a Sl-subtype in the SMASS taxonomy.[1]

Rotation period[edit]

The first rotational lightcurve of Bruce Helin was obtained from photometric observations by Czech astronomer Petr Pravec in September 2006. The lightcurve showed a rotation period of 128 hours with a brightness variation of 0.60 in magnitude (U=2).[a] Later observations rendered a similar rotation period of 129.75 and 129.42 hours, respectively (U=n.a./2).[7][6]

Diameter and albedo[edit]

According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its NEOWISE mission, Bruce Helin measures 11.8 and 12.5 kilometers in diameter, and its surface has an albedo of 0.18 and 0.24, respectively.[4][5] The Collaborative Asteroid Lightcurve Link (CALL) assumes an albedo of 0.23 and calculates a diameter of 12.1 kilometers with an absolute magnitude of 11.8.[3]

This minor planet was named after Bruce Helin, son of the first discover Eleanor Helin, in an expression of gratitude for "the many years he tolerated his mother's preoccupation with extraterrestrial objects".[2] The discoverer has also honoured her daughter-in-law and wife of Bruce, Nancy Coker Helin, by the minor planet 4222 Nancita.[10] The approved naming citation was published by the Minor Planet Center on 13 October 1981 (M.P.C. 6421).[11]


  1. ^ a b Pravec (2006) web: rotation period 128 hours with a brightness amplitude of 0.6 mag. Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (2430) Bruce Helin


  1. ^ a b c d e f g h i "JPL Small-Body Database Browser: 2430 Bruce Helin (1977 VC)" (2016-10-11 last obs.). Jet Propulsion Laboratory. Retrieved 3 July 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (2430) Bruce Helin. Springer Berlin Heidelberg. p. 198. ISBN 978-3-540-00238-3. Retrieved 2 May 2016. 
  3. ^ a b c d e f "LCDB Data for (2430) Bruce Helin". Asteroid Lightcurve Database (LCDB). Retrieved 2 May 2016. 
  4. ^ a b c d Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. Retrieved 2 May 2016. 
  5. ^ a b c d Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (November 2012). "Preliminary Analysis of WISE/NEOWISE 3-Band Cryogenic and Post-cryogenic Observations of Main Belt Asteroids". The Astrophysical Journal Letters. 759 (1): 5. Bibcode:2012ApJ...759L...8M. arXiv:1209.5794Freely accessible. doi:10.1088/2041-8205/759/1/L8. Retrieved 2 May 2016. 
  6. ^ a b c Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. Bibcode:2015AJ....150...75W. arXiv:1504.04041Freely accessible. doi:10.1088/0004-6256/150/3/75. Retrieved 2 May 2016. 
  7. ^ a b Hanus, J.; Broz, M.; Durech, J.; Warner, B. D.; Brinsfield, J.; Durkee, R.; et al. (November 2013). "An anisotropic distribution of spin vectors in asteroid families". Astronomy and Astrophysics. 559: 19. Bibcode:2013A&A...559A.134H. arXiv:1309.4296Freely accessible. doi:10.1051/0004-6361/201321993. Retrieved 2 May 2016. 
  8. ^ Veres, Peter; Jedicke, Robert; Fitzsimmons, Alan; Denneau, Larry; Granvik, Mikael; Bolin, Bryce; et al. (November 2015). "Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results". Icarus. 261: 34–47. Bibcode:2015Icar..261...34V. arXiv:1506.00762Freely accessible. doi:10.1016/j.icarus.2015.08.007. Retrieved 2 May 2016. 
  9. ^ a b "2430 Bruce Helin (1977 VC)". Minor Planet Center. Retrieved 2 May 2016. 
  10. ^ Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (4222) Nancita. Springer Berlin Heidelberg. p. 361. ISBN 978-3-540-29925-7. Retrieved 1 January 2016. 
  11. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 2 May 2016. 

External links[edit]