23712 Willpatrick

23712 Willpatrick
Discovery [1]
Discovered by W. G. Dillon
E. R. Dillon
Discovery site George Obs. (735)
Discovery date 1 January 1998
Designations
MPC designation 23712 Willpatrick
Named after
 William Dillon
(discoverer's son)[2]
1998 AA
main-belt · Phocaea [3]
Orbital characteristics [1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc 62.20 yr (22,717 days)
Aphelion 2.9614 AU
Perihelion 1.7881 AU
2.3747 AU
Eccentricity 0.2470
3.66 yr (1,337 days)
161.84°
0° 16m 9.48s / day
Inclination 23.493°
246.43°
85.270°
Physical characteristics
Dimensions 5.28 km (calculated)[3]
7.660±0.187 km[4][5]
3.902±0.005 h[6]
0.1198±0.0272[4]
0.120±0.027[5]
0.23 (assumed)[3]
S [3]
13.6[1][3] · 13.5[4]
13.85±0.23[7]

    23712 Willpatrick, provisional designation 1998 AA, is a stony Phocaea asteroid from the inner regions of the asteroid belt, approximately 7 kilometers in diameter. It was discovered on 1 January 1998, by American astronomers Elizabeth and William G. Dillon at George Observatory in Needville, Texas.[8]

    The stony S-type asteroid is a member of the Phocaea family, a group of asteroids with similar orbital characteristics.[3] It orbits the Sun at a distance of 1.8–3.0 AU once every 3 years and 8 months (1,337 days). Its orbit has an eccentricity of 0.25 and an inclination of 23° with respect to the ecliptic.[1] The first precovery was taken during the Digitized Sky Survey at Palomar Observatory in 1954, extending Willpatrick's observation arc by 44 years prior to its official discovery obervation.[8]

    A rotational light-curve was obtained by American astronomer Brian D. Warner at his Palmer Divide Observatory (716) in September 2004. The photometric obervations rendered a well-defined rotation period of 3.902±0.005 hours with a brightness variation of 0.40 magnitude (U=3).[6] According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Willpatrick measures 7.7 kilometers in diameter and its surface has an albedo of 0.12,[4][5] while the Collaborative Asteroid Lightcurve Link assumes a higher albedo of 0.23 – derived from 25 Phocaea, the namesake of the Phocaea family – and calculates a diameter of 5.3 kilometers, based on an absolute magnitude of 13.6.[3]

    The minor planet was named after the discoverer's son, William Patrick Dillon (b. 1992), who was present on the night this minor planet was discovered. His words "Daddy, I want to go home now. This place is cold and spooky." made it into the naming citation of the Minor Planet Circulars (MPCs).[2] Naming citation was published on 28 September 2004 (M.P.C. 52769).[9]

    References

    1. 1 2 3 4 "JPL Small-Body Database Browser: 23712 Willpatrick (1998 AA)" (2016-03-15 last obs.). Jet Propulsion Laboratory. Retrieved 3 December 2016.
    2. 1 2 Schmadel, Lutz D. (2006). Dictionary of Minor Planet Names – (23712) Willpatrick, Addendum to Fifth Edition: 2003–2005. Springer Berlin Heidelberg. p. 186. ISBN 978-3-540-34360-8. Retrieved 1 January 2016.
    3. 1 2 3 4 5 6 7 "LCDB Data for (23712) Willpatrick". Asteroid Lightcurve Database (LCDB). Retrieved 17 May 2016.
    4. 1 2 3 4 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:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 17 May 2016.
    5. 1 2 3 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:1109.4096Freely accessible. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 3 December 2016.
    6. 1 2 Warner, Brian D. (June 2005). "Asteroid lightcurve analysis at the Palmer Divide Observatory - fall 2004". The Minor Planet Bulletin. 32 (2): 29–32. Bibcode:2005MPBu...32...29W. ISSN 1052-8091. Retrieved 17 May 2016.
    7. ↑ 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:1506.00762Freely accessible. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 17 May 2016.
    8. 1 2 "23712 Willpatrick (1998 AA)". Minor Planet Center. Retrieved 1 January 2016.
    9. ↑ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 17 May 2016.

    External links

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