1368 Numidia, provisional designation 1935 HD, is a stony background asteroid from the central regions of the asteroid belt, approximately 19 kilometers in diameter. It was discovered on 30 April 1935, by South African astronomer Cyril Jackson at the Union Observatory in Johannesburg.[15] The asteroid was named after the ancient North African kingdom of Numidia.[3]

1368 Numidia
Modelled shape of Numidia from its lightcurve
Discovery[1]
Discovered byC. Jackson
Discovery siteJohannesburg Obs.
Discovery date30 April 1935
Designations
(1368) Numidia
Pronunciation/njˈmɪdiə/[2]
Named after
Numidia[3]
(ancient Berber kingdom)
1935 HD · 1928 SN
1931 JF · 1935 KB
1936 QN · 1953 YK
main-belt · (inner)[4]
background[5] · Maria[6]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc86.45 yr (31,577 days)
Aphelion2.6814 AU
Perihelion2.3673 AU
2.5243 AU
Eccentricity0.0622
4.01 yr (1,465 days)
146.05°
0° 14m 44.52s / day
Inclination14.823°
18.130°
264.36°
Physical characteristics
Dimensions15.93±0.37 km[7]
19.24 km (derived)[4]
19.29±0.9 km[8]
19.591±0.213 km[9]
19.899±0.110 km[10]
20.66±0.82 km[11]
3.64 h[12]
3.640739 h[13]
3.640740 h[14]
0.177±0.016[11]
0.1838±0.0295[10]
0.1918 (derived)[4]
0.2035±0.019[8]
0.298±0.021[7]
S (assumed)[4]
B–V = 0.860[1]
U–B = 0.360[1]
10.92[1][7][8][11] · 10.99[4][10][12]

Orbit and classification

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Based on the hierarchical clustering method, Numidia has both been classified as a non-family asteroid from the main belt's background population (Nesvorný),[5] and as a core member of the Maria family (Milani and Knežević).[6] It orbits the Sun in the intermediate asteroid belt at a distance of 2.4–2.7 AU once every 4.01 years (1,465 days; semi-major axis of 2.52 AU). Its orbit has an eccentricity of 0.06 and an inclination of 15° with respect to the ecliptic.[1]

The asteroid was first identified as 1928 SN at Uccle Observatory in September 1928. The body's observation arc begins at Johannesburg in May 1931, three weeks after its official discovery observation.[15]

Naming

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This minor planet was named after the ancient Berber kingdom of Numidia, that was located in North Africa, in what is now Algeria. The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 124).[3]

Physical characteristics

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Numidia is an assumed stony S-type asteroid.[4]

Rotation period and poles

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In May 1983, a first rotational lightcurve of Numidia was obtained from photometric observations by American astronomer Richard Binzel. Lightcurve analysis gave a well-defined rotation period of 3.64 hours with a brightness amplitude of 0.35 magnitude (U=3).[12]

Modeling of the asteroid's lightcurve gave a concurring sidereal period of 3.640739 and 3.640740 hours, respectively.[13][14] In 2016, modeling also determined a pole of (201.0°, −62.0°) in ecliptic coordinates (λ, β).[13]

Diameter and albedo

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According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Numidia measures between 15.93 and 20.66 kilometers in diameter and its surface has an albedo between 0.177 and 0.298.[7][8][9][10][11]

The Collaborative Asteroid Lightcurve Link derives an albedo of 0.1918 and a diameter of 19.24 kilometers based on an absolute magnitude of 10.99.[4]

References

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  1. ^ a b c d e f "JPL Small-Body Database Browser: 1368 Numidia (1935 HD)" (2017-11-01 last obs.). Jet Propulsion Laboratory. Retrieved 9 November 2017.
  2. ^ "Numidian". Oxford English Dictionary (Online ed.). Oxford University Press. (Subscription or participating institution membership required.)
  3. ^ a b c Schmadel, Lutz D. (2007). "(1368) Numidia". Dictionary of Minor Planet Names – (1368) Numidia. Springer Berlin Heidelberg. p. 111. doi:10.1007/978-3-540-29925-7_1369. ISBN 978-3-540-00238-3.
  4. ^ a b c d e f g "LCDB Data for (1368) Numidia". Asteroid Lightcurve Database (LCDB). Retrieved 9 November 2017.
  5. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Archived from the original on 2 August 2017. Retrieved 9 November 2017.
  6. ^ a b "Asteroid 1368 Numidia – Proper Elements". AstDyS-2, Asteroids – Dynamic Site. Retrieved 29 October 2019.
  7. ^ a b c d Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Nugent, C.; et al. (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 9 November 2017.
  8. ^ a b c d Tedesco, E. F.; Noah, P. V.; Noah, M.; Price, S. D. (October 2004). "IRAS Minor Planet Survey V6.0". NASA Planetary Data System. 12: IRAS-A-FPA-3-RDR-IMPS-V6.0. Bibcode:2004PDSS...12.....T. Retrieved 22 October 2019.
  9. ^ a b Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 9 November 2017.
  10. ^ 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.
  11. ^ 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)
  12. ^ a b c Binzel, R. P. (October 1987). "A photoelectric survey of 130 asteroids". Icarus. 72 (1): 135–208. Bibcode:1987Icar...72..135B. doi:10.1016/0019-1035(87)90125-4. ISSN 0019-1035. Retrieved 9 November 2017.
  13. ^ a b c 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.
  14. ^ a b Hanus, J.; Durech, J.; Broz, M.; Warner, B. D.; Pilcher, F.; Stephens, R.; et al. (June 2011). "A study of asteroid pole-latitude distribution based on an extended set of shape models derived by the lightcurve inversion method". Astronomy & Astrophysics. 530: 16. arXiv:1104.4114. Bibcode:2011A&A...530A.134H. doi:10.1051/0004-6361/201116738. Retrieved 9 November 2017.
  15. ^ a b "1368 Numidia (1935 HD)". Minor Planet Center. Retrieved 9 November 2017.
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