_Somalia.png) Modelled shape of Somalia from its
lightcurve | |
| Discovery [1] | |
|---|---|
| Discovered by | C. Jackson |
| Discovery site | Johannesburg Obs. |
| Discovery date | 5 July 1937 |
| Designations | |
| (1430) Somalia | |
Named after | Somalia [2] (African country) |
| 1937 NK · 1929 RQ 1954 UR1 · 1957 HT 1962 VF | |
|
main-belt · (
middle) background [3] · Astraea [4] | |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 ( JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 79.73 yr (29,122 days) |
| Aphelion | 3.0674 AU |
| Perihelion | 2.0508 AU |
| 2.5591 AU | |
| Eccentricity | 0.1986 |
| 4.09 yr (1,495 days) | |
| 184.53 ° | |
| 0° 14m 26.88s / day | |
| Inclination | 3.2883° |
| 327.25° | |
| 351.42° | |
| Physical characteristics | |
| Dimensions | 8.77±1.58 km
[5] 9.352±0.133 km [6] 9.44±0.36 km [7] 9.674±0.089 km [8] 10.79 km (calculated) [9] |
| 6.90907±0.00005 h
[10] 6.910±0.001 h [11] 6.913±0.001 h [12] | |
| 0.1436±0.0287
[8] 0.153±0.032 [6] 0.162±0.014 [7] 0.20 (assumed) [9] 0.31±0.14 [5] | |
| S (assumed) [9] | |
| 12.1 [1] · 12.2 [9] · 12.35±0.35 [13] · 12.41 [5] · 12.80 [7] [8] | |
1430 Somalia, provisional designation 1937 NK, is a stony background asteroid from the central regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 5 July 1937, by astronomer Cyril Jackson at the Union Observatory in Johannesburg. [14] It was named for the African country of Somalia. [2]
Orbit and classification
Based on the hierarchical clustering method, Somalia is a non- family asteroid of the main belt's background population (Nesvorný), [3] as well as a core member of the Astraea family (Milani and Knežević). [4] It orbits the Sun in the central asteroid belt at a distance of 2.1–3.1 AU once every 4 years and 1 month (1,495 days). Its orbit has an eccentricity of 0.20 and an inclination of 3 ° with respect to the ecliptic. [1]
The asteroid was first identified as 1929 RQ at Simeiz or Lowell observatories in September 1929. The body's observation arc begins with its official discovery observation at Johannesburg in 1937. [14]
Physical characteristics
Somalia is an assumed stony S-type asteroid. [9]
Lightcurves
In 2011, two rotational lightcurves of Somalia were obtained from photometric observations by French amateur astronomer René Roy, and by astronomers at the Bassano Bresciano Observatory ( 565) in Italy. Lightcurve analysis gave a rotation period of 6.910 and 6.913 hours with a brightness amplitude of 0.40 and 0.45 magnitude, respectively ( U=3-/3). [11] [12]
In 2016, a modeled lightcurve was derived from various photometric database sources, giving a concurring sidereal period of 6.90907 hours. The modelled lightcurve also determined two spin axis of (297.0°, 42.0°) and (128.0°, 47.0°) in ecliptic coordinates. [10]
Diameter and albedo
According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Somalia measures between 8.77 and 9.674 kilometers in diameter and its surface has an albedo between 0.1436 and 0.31. [5] [6] [7] [8]
The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 10.79 kilometers based on an absolute magnitude of 12.2. [9]
Naming
This minor planet was named after the country of Somalia, located in the Horn of Africa. [2] The official naming citation was published by the Minor Planet Center on 1 February 1980 ( M.P.C. 5181). [15]
References
- ^ a b c d "JPL Small-Body Database Browser: 1430 Somalia (1937 NK)" (2017-03-29 last obs.). Jet Propulsion Laboratory. Retrieved 26 October 2017.
- ^ a b c Schmadel, Lutz D. (2007). "(1430) Somalia". Dictionary of Minor Planet Names – (1430) Somalia. Springer Berlin Heidelberg. p. 115. doi: 10.1007/978-3-540-29925-7_1431. ISBN 978-3-540-00238-3.
- ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Archived from the original on 2 August 2017. Retrieved 26 October 2017.
- ^ a b "Asteroid 1430 Somalia – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 29 October 2019.
- ^ a b c d Nugent, C. R.; Mainzer, A.; Bauer, J.; Cutri, R. M.; Kramer, E. A.; Grav, T.; et al. (September 2016). "NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos". The Astronomical Journal. 152 (3): 12. arXiv: 1606.08923. Bibcode: 2016AJ....152...63N. doi: 10.3847/0004-6256/152/3/63.
- ^ 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. S2CID 118745497. Retrieved 26 October 2017.
- ^ a b c d 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. ( online, AcuA catalog p. 153)
- ^ 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. S2CID 35447010.
- ^ a b c d e f "LCDB Data for (1430) Somalia". Asteroid Lightcurve Database (LCDB). Retrieved 26 October 2017.
- ^ a b Hanus, J.; Durech, J.; Oszkiewicz, D. A.; Behrend, R.; Carry, B.; Delbo, M.; et al. (February 2016). "New and updated convex shape models of asteroids based on optical data from a large collaboration network". Astronomy and Astrophysics. 586: 24. arXiv: 1510.07422. Bibcode: 2016A&A...586A.108H. doi: 10.1051/0004-6361/201527441. S2CID 119112278.
- ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1430) Somalia". Geneva Observatory. Retrieved 26 October 2017.
- ^ a b Strabla, Luca; Quadri, Ulisse; Girelli, Roberto (July 2012). "Lightcurve Analysis for Eight Minor Palnets at Bassano Bresciano Observatory". The Minor Planet Bulletin. 39 (3): 177–179. Bibcode: 2012MPBu...39..177S. ISSN 1052-8091. Retrieved 26 October 2017.
- ^ 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. S2CID 53493339. Retrieved 26 October 2017.
- ^ a b "1430 Somalia (1937 NK)". Minor Planet Center. Retrieved 26 October 2017.
- ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 26 October 2017.
External links
- Asteroid Lightcurve Database (LCDB), query form ( info Archived 16 December 2017 at the Wayback Machine)
- 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
- 1430 Somalia at AstDyS-2, Asteroids—Dynamic Site
- 1430 Somalia at the JPL Small-Body Database
