4151 Alanhale

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4151 Alanhale
Discovery [1]
Discovered byC. S. Shoemaker
E. M. Shoemaker
Discovery sitePalomar Obs.
Discovery date24 April 1985
MPC designation(4151) Alanhale
Named after
Alan Hale (astronomer)[2]
1985 HV1 · 1968 HD
1976 SO1 · 1979 FX1
1982 SZ4 · 1985 JX
main-belt · Themis[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc48.95 yr (17,878 days)
Aphelion3.5904 AU
Perihelion2.7017 AU
3.1461 AU
5.58 yr (2,038 days)
0° 10m 35.76s / day
Physical characteristics
Dimensions15.37 km (calculated)[3]
19.526±0.269 km[4][5]
22.66±0.59 km[6]
11.9177±0.0047 h[7]
0.08 (assumed)[3]
11.976±0.003 (R)[7] · 12.0[4] · 12.20[6] · 12.3[1] · 12.43[3] · 12.78±0.21[8]

4151 Alanhale, provisional designation 1985 HV1, is a carbonaceous Themistian asteroid from the outer region of the asteroid belt, approximately 19 kilometers in diameter. It was discovered by the American astronomer couple Carolyn and Eugene Shoemaker at the U.S. Palomar Observatory, California, on 24 April 1985.[9] It was named for American astronomer Alan Hale.[2]

Orbit and classification[edit]

Alanhale is a member of the Themis family, a dynamical family of outer-belt asteroids with nearly coplanar ecliptical orbits. It orbits the Sun in the outer main-belt at a distance of 2.7–3.6 AU once every 5 years and 7 months (2,038 days). Its orbit has an eccentricity of 0.14 and an inclination of 1° with respect to the ecliptic.[1] It was first identified as 1968 HD at Zimmerwald Observatory in 1968, extending the body's observation arc by 17 years prior to its official discovery observation at Palomar.[9]

Physical characteristics[edit]

Alanhale has been characterized as a dark C-type asteroid by PanSTARRS' photometric survey.[3][8]

Rotation period[edit]

A rotational lightcurve of Alanhale was obtained from photometric observations made at the U.S. Palomar Transient Factory in October 2010. The fragmentary lightcurve gave a rotation period of 11.9177±0.0047 hours with a low brightness variation of 0.07 in magnitude (U=1).[7]

Diameter and albedo[edit]

According to the surveys carried out by NASA's spaced-based Wide-field Infrared Survey Explorer and its subsequent NEOWISE mission, Alanhale measures 19.5 and 22.7 kilometers in diameter, respectively, with a corresponding albedo of 0.07 and 0.05.[4][5][6] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.08 and calculates a smaller diameter of 15.4 kilometers with an absolute magnitude of 12.43.[3]


This minor planet was named in honor of American astronomer Alan Hale (born 1958), co-discoverer of comet Hale–Bopp.[2]

His precise visual observations include more than 130 comets, several at more than one apparition, and both, magnitude estimates and confirmations of discoveries. He has also skillfully estimated the magnitudes of the near-Earth objects, 4179 Toutatis and (99907) 1989 VA, and has performed asteroid occultation. Hale has promoted the study of small Solar System bodies in articles and in his astronomy lectures.[2] The official naming citation was published by the Minor Planet Center on 28 April 1991 (M.P.C. 18139).[10]


  1. ^ a b c d "JPL Small-Body Database Browser: 4151 Alanhale (1985 HV1)" (2017-03-29 last obs.). Jet Propulsion Laboratory. Retrieved 20 June 2017.
  2. ^ a b c d Schmadel, Lutz D. (2007). "(4151) Alanhale". Dictionary of Minor Planet Names – (4151) Alanhale. Springer Berlin Heidelberg. p. 355. doi:10.1007/978-3-540-29925-7_4123. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f g "LCDB Data for (4151) Alanhale". Asteroid Lightcurve Database (LCDB). Retrieved 4 May 2016.
  4. ^ a b c d Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 4 May 2016.
  5. ^ a b c Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J.; et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal. 741 (2): 20. arXiv:1109.4096. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 5 December 2016.
  6. ^ 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. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 4 May 2016.
  7. ^ 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. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 4 May 2016.
  8. ^ a b c 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. arXiv:1506.00762. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 4 May 2016.
  9. ^ a b "4151 Alanhale (1985 HV1)". Minor Planet Center. Retrieved 4 May 2016.
  10. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 4 May 2016.

External links[edit]