Misplaced Pages

9549 Akplatonov, provisional designation 1985 SM₂, is an Eunomia asteroid from the central region of the asteroid belt, approximately 8.2 kilometers (5.1 miles) in diameter. It was discovered on 19 September 1985, by Soviet–Russian astronomer couple Nikolai and Lyudmila Chernykh at the Crimean Astrophysical Observatory in Nauchnyj, on the Crimean peninsula. The likely S-type asteroid has a relatively short rotation period of 2.8 hours. It was named for Russian computational mathematician Aleksandr Platonov.

Orbit and classification

Akplatonov is a core member of the Eunomia family, a large group of stony S-type asteroids and the most prominent family in the intermediate main-belt. Alternatively, in Nesvorný's HCM-analysis, the asteroid belong's to the main belt's background population, while in an earlier such analysis, Thais Mothé-Diniz considered Akplatonov to be the largest body in a small cluster or clump of its own. It orbits the Sun in the central asteroid belt at a distance of 2.3–2.9 AU once every 4 years and 3 months (1,537 days; semi-major axis of 2.61 AU). Its orbit has an eccentricity of 0.11 and an inclination of 11° with respect to the ecliptic. The body's observation arc begins 4 years prior to its official discovery observation, with its first identification as 1981 TU₁ at the discovering observatory in October 1981.

Naming

This minor planet was named in honor of Aleksandr Konstantinovich Platonov (born 1931), a Russian computational mathematician, roboticist, astrodynamicist, and long-time member at the Keldysh Institute of Applied Mathematics. He pioneered the research in walking robots, the computation of satellite orbits around Earth, and the guidance of the flight path of spacecraft in the Solar System. The official naming citation was published by the Minor Planet Center on 24 June 2002 (M.P.C. 46009).

Physical characteristics

Rotation period

A rotational lightcurve of Akplatonov was obtained from photometric observations using the 0.9-meter SARA telescope at Kitt Peak National Observatory in May 2009. It showed a rotation period of 2.8431±0.0004 hours with a brightness variation of 0.15 magnitude (U=3-). A poorly rated period determination from a fragmentary lightcurve by astronomers at the Palomar Transient Factory in 2010 gave a period of 4.7 hours (U=1).

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's space-based Wide-field Infrared Survey Explorer, Akplatonov measures 8.2 kilometers in diameter and its surface has an albedo of 0.285, while the Collaborative Asteroid Lightcurve Link (CALL) assumes an albedo of 0.21 – derived from 15 Eunomia, the family's largest member and namesake – and calculates a diameter of 9.17 kilometers using an absolute magnitude of 12.5.

References

1. ^ "9549 Akplatonov (1985 SM2)". Minor Planet Center. Retrieved 16 January 2019.
2. ^ Schmadel, Lutz D. (2007). "(9549) Akplatonov". Dictionary of Minor Planet Names – (9549) Akplatonov. Springer Berlin Heidelberg. p. 698. doi:10.1007/978-3-540-29925-7_7578. ISBN 978-3-540-00238-3.
3. ^ "JPL Small-Body Database Browser: 9549 Akplatonov (1985 SM2)" (2018-10-15 last obs.). Jet Propulsion Laboratory. Retrieved 16 January 2019.
4. ^ "Asteroid 9549 Akplatonov". Small Bodies Data Ferret. Retrieved 16 January 2019.
5. ^ "Asteroid (9549) Akplatonov – Proper elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 16 January 2019.
6. ^ "LCDB Data for (9549) Akplatonov". Asteroid Lightcurve Database (LCDB). Retrieved 16 January 2019.
7. ^ Mainzer, A. K.; Bauer, J. M.; Cutri, R. M.; Grav, T.; Kramer, E. A.; Masiero, J. R.; et al. (June 2016). "NEOWISE Diameters and Albedos V1.0". NASA Planetary Data System: EAR-A-COMPIL-5-NEOWISEDIAM-V1.0. Bibcode:2016PDSS..247.....M. Retrieved 16 January 2019.
8. ^ 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. S2CID 118745497.
9. ^ 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. S2CID 35447010. (catalog)
10. ^ Murphy, Brian W.; Darragh, Andrew N.; Harp, Thomas W.; Liu, Zheyu J.; Geiss, Brian B.; Lawder, Matthew T.; et al. (July 2011). "Lightcurve Analysis of Asteroids (6577) 1978 VB6, 6619 Kolya, 9549 Akplatonov, (12466) 1997 AS12, (15154) 2000 FW30, and (32505) 2001 KF17". The Minor Planet Bulletin. 38 (3): 139–140. Bibcode:2011MPBu...38..139M. ISSN 1052-8091.
11. "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 16 January 2019.
12. 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. S2CID 8342929.

External links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Discovery Circumstances: Numbered Minor Planets (5001)-(10000) – Minor Planet Center
• 9549 Akplatonov at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 9549 Akplatonov at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit viewer · Orbit parameters · Physical parameters

• Minor planet object articles (numbered)
• Eunomia asteroids
• Background asteroids
• Discoveries by Nikolai Chernykh
• Discoveries by Lyudmila Chernykh
• Named minor planets
• Astronomical objects discovered in 1985