4949 Akasofu
| Discovery [1] | |
|---|---|
| Discovered by | T. Kojima |
| Discovery site | YGCO Chiyoda Stn. |
| Discovery date | 29 November 1988 |
| Designations | |
| MPC designation | 4949 Akasofu |
Named after |
Syun-Ichi Akasofu (geophysicist)[2] |
|
1988 WE · 1978 YE 1981 RL5 · 1981 SV6 | |
| main-belt · Flora [3] | |
| Orbital characteristics [1] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 37.05 yr (13,534 days) |
| Aphelion | 2.6551 AU |
| Perihelion | 1.8887 AU |
| 2.2719 AU | |
| Eccentricity | 0.1687 |
| 3.42 yr (1,251 days) | |
| 48.384° | |
| 0° 17m 16.08s / day | |
| Inclination | 4.8115° |
| 108.7226° | |
| 275.2366° | |
| Physical characteristics | |
| Dimensions |
4.460±0.181 km[4] 5.67 km (calculated)[3] |
|
2.6798±0.0002 h[5] 2.6800±0.0003 h[lower-alpha 1] | |
|
0.3224±0.0552[4] 0.24 (assumed)[3] | |
| S [3] | |
|
13.4[1][3] 13.6[4] 13.49±0.14[6] | |
|
| |
4949 Akasofu, provisional designation 1988 WE, is a stony Flora asteroid from the inner regions of the asteroid belt, about 5 kilometers in diameter. It was discovered by Japanese amateur astronomer Takuo Kojima at the YGCO Chiyoda Station in Japan on 29 November 1988.[7]
The S-type asteroid is a member of the Flora family, one of the largest groups of stony asteroids in the main-belt. It orbits the Sun at a distance of 1.9–2.7 AU once every 3 years and 5 months (1,251 days). Its orbit has an eccentricity of 0.17 and an inclination of 5 degrees with respect to the plane of the ecliptic.[1] The first precovery was obtained at the Purple Mountain Observatory in 1978, extending the asteroid's observation arc by 10 years prior to its discovery.[7]
According to the survey carried out by the NEOWISE mission of NASA's space-based Wide-field Infrared Survey Explorer, the asteroid measures 4.5 kilometers in diameter and its surface has an albedo of 0.32,[4] while the Collaborative Asteroid Lightcurve Link assumes an intermediate albedo of 0.24 – which derives from 8 Flora, the largest member and namesake of this orbital family – and calculates a diameter of 5.7 kilometers, based on an absolute magnitude of 13.4.[3]
In October 2005, a rotational light-curve of this asteroid was obtained from photometric observations made by David Higgins at Hunters Hill Observatory, Australia. It showed a rotation period of 2.6798±0.0002 hours with a brightness variation of 0.10 in magnitude (U=3).[5] Observations by Czech astronomer Petr Pravec in March 2007, gave another well-defined and concurring light-curve with a period of 2.6800±0.0003 hours and an amplitude of 0.15 in magnitude (U=3).[lower-alpha 1]
The minor planet was named in honor of Japanese-born geophysicist Syun-Ichi Akasofu (b. 1930), professor at University of Alaska Fairbanks. He was the director of the International Arctic Research Center from 1998 to 2007, and is known for studies of the aurora borealis.[2] Naming citation was published on 30 March 2010 (M.P.C. 69491).[8]
References
- 1 2 Pravec (2007) web: rotation period 2.6800±0.0003 hours with a brightness amplitude of 0.15 magnitude. Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (4949) Akasofu
- 1 2 3 4 "JPL Small-Body Database Browser: 4949 Akasofu (1988 WE)" (2016-01-12 last obs.). Jet Propulsion Laboratory. Retrieved 3 May 2016.
- 1 2 Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names – (4949) Akasofu. Springer Berlin Heidelberg. p. 402. ISBN 978-3-540-29925-7. Retrieved 30 December 2015.
- 1 2 3 4 5 6 "LCDB Data for (4949) Akasofu". Asteroid Lightcurve Database (LCDB). Retrieved 3 May 2016.
- 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:1109.6407
. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 3 May 2016. - 1 2 Higgins, David; Pravec, Petr; Kusnirak, Peter; Masi, Gianluca; Galad, Adrian; Gajdos, Stefan; et al. (March 2006). "Asteriod [sic] lightcurve analysis at Hunters Hill Observatory and collaborating stations - autumn/winter 2005". The Minor Planet Bulletin. 33 (1): 8–10. Bibcode:2006MPBu...33....8H. ISSN 1052-8091. Retrieved 3 May 2016.
- ↑ 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 3 May 2016.
- 1 2 "4949 Akasofu (1988 WE)". Minor Planet Center. Retrieved 3 May 2016.
- ↑ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 3 May 2016.
External links
- Asteroid Lightcurve Database (LCDB), query form (info)
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- 4949 Akasofu at the JPL Small-Body Database
