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1430 Somalia

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1430 Somalia
Modelled shape of Somalia from its lightcurve
Discovery[1]
Discovered byC. Jackson
Discovery siteJohannesburg Obs.
Discovery date5 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 arc79.73 yr (29,122 days)
Aphelion3.0674 AU
Perihelion2.0508 AU
2.5591 AU
Eccentricity0.1986
4.09 yr (1,495 days)
184.53°
0° 14m 26.88s / day
Inclination3.2883°
327.25°
351.42°
Physical characteristics
Dimensions8.77±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

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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

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Somalia is an assumed stony S-type asteroid.[9]

Lightcurves

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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

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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

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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

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  1. ^ 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.
  2. ^ 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.
  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.
  4. ^ a b "Asteroid 1430 Somalia – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 29 October 2019.
  5. ^ 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.
  6. ^ 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.
  7. ^ 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)
  8. ^ 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.
  9. ^ a b c d e f "LCDB Data for (1430) Somalia". Asteroid Lightcurve Database (LCDB). Retrieved 26 October 2017.
  10. ^ 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.
  11. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1430) Somalia". Geneva Observatory. Retrieved 26 October 2017.
  12. ^ 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.
  13. ^ 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.
  14. ^ a b "1430 Somalia (1937 NK)". Minor Planet Center. Retrieved 26 October 2017.
  15. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 26 October 2017.
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