1999 Hirayama
| Discovery [1] | |
|---|---|
| Discovered by | L. Kohoutek |
| Discovery site | Bergedorf Obs. |
| Discovery date | 27 February 1973 |
| Designations | |
| MPC designation | 1999 Hirayama |
Named after |
Kiyotsugu Hirayama (astronomer)[2] |
|
1973 DR · 1935 GF 1940 EH · 1951 EY1 1951 FA · 1965 UF 1969 NB · 1975 NE | |
| main-belt · (outer) [3] | |
| Orbital characteristics [1] | |
| Epoch 27 June 2015 (JD 2457200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 75.70 yr (27,649 days) |
| Aphelion | 3.4711 AU |
| Perihelion | 2.7585 AU |
| 3.1148 AU | |
| Eccentricity | 0.1143 |
| 5.50 yr (2,008 days) | |
| 256.17° | |
| Inclination | 12.534° |
| 148.04° | |
| 356.78° | |
| Physical characteristics | |
| Dimensions |
33.95 km[4] 35.68±0.55 km[5] 38.28±0.40 km[6] 33.81 km (derived)[3] |
| Mass | 4.1×1016 kg |
|
15.63±0.01 h[7] 22.37±0.03 h[8] 13.5921±0.0003 h[lower-alpha 1] | |
|
0.0882[4] 0.082±0.003[5] 0.053±0.005[6] 0.0675 (derived)[3] | |
| C [3] | |
|
11.0 10.6[7] | |
|
| |
1999 Hirayama, provisional designation 1973 DR, is a carbonaceous asteroid from the outer region of the asteroid belt, about 34 kilometers in diameter. It was discovered by Czech astronomer Luboš Kohoutek at the Hamburger Bergedorf Observatory, Germany, on 27 February 1973.[9]
The C-type asteroid orbits the Sun at a distance of 2.8–3.5 AU once every five and a half years (2,008 days). Its orbit shows an eccentricity of 0.11 and is tilted by 13 degrees to the plane of the ecliptic. According to the surveys carried out by the space-based IRAS, Akari and WISE satellites and the subsequent NEOWISE mission, the body's surface has an albedo in the range of 0.05–0.09.[4][5][6]
The light curve analysis showed a periodicity of 15.63±0.01 hours, during which time the brightness of the object varies by 0.45±0.04 in magnitude.[7] The spectrum of this object matches a C-type Tholen classification, but with a "broad absorption band that can be associated to a process of aqueous alteration".[10] That is, the surface appears to show some form of water modification. A more recent observations rendered a somewhat shorter period of 13.6 hours.[lower-alpha 1]
The minor planet is named in honour of Japanese astronomer Kiyotsugu Hirayama (1874–1943), best known for his discovery that many asteroid orbits were more similar to one another than chance would allow, leading to the concept of asteroid families, now called Hirayama families. The lunar carter Hirayama is also named in his honour.[2]
References
- 1 2 Hamanowa (2011) web: rotation period 13.5921±0.0003 hours with a brightness amplitude of 0.57 mag. Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (1999) Hirayama
- 1 2 "JPL Small-Body Database Browser: 1999 Hirayama (1973 DR)" (2015-11-20 last obs.). Jet Propulsion Laboratory. Retrieved December 2015.
- 1 2 Schmadel, Lutz D. (2003). Dictionary of Minor Planet Names – (1999) Hirayama. Springer Berlin Heidelberg. p. 162. ISBN 978-3-540-29925-7. Retrieved October 2015.
- 1 2 3 4 "LCDB Data for (1999) Hirayama". Asteroid Lightcurve Database (LCDB). Retrieved December 2015.
- 1 2 3 Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. Bibcode:2004PDSS...12.....T. Retrieved December 2015.
- 1 2 3 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 December 2015.
- 1 2 3 Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; Cabrera, M. S. (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 December 2015.
- 1 2 3 Menke, John; Cooney, Walt; Gross, John; Terrell, Dirk; Higgins, David (October 2008). "Asteroid Lightcurve Analysis at Menke Observatory". Bulletin of the Minor Planets (Section of the Association of Lunar and Planetary Observers) 35 (4): 155–160. Bibcode:2008MPBu...35..155M. ISSN 1052-8091. Retrieved December 2015.
- ↑ Behrend, Raoul. "Asteroids and comets rotation curves – (1999) Hirayama". Geneva Observatory. Retrieved December 2015.
- ↑ "1999 Hirayama (1973 DR)". Minor Planet Center. Retrieved October 2015.
- ↑ Lazzaro, D.; et al. (November 2004), "S3OS2: the visible spectroscopic survey of 820 asteroids", Icarus 172 (1): 179–220, Bibcode:2004Icar..172..179L, doi:10.1016/j.icarus.2004.06.006.
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
- 1999 Hirayama at the JPL Small-Body Database
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