1355 Magoeba

From Wikipedia, the free encyclopedia
Jump to: navigation, search
1355 Magoeba
Discovery [1]
Discovered by C. Jackson
Discovery site Johannesburg Obs.
Discovery date 30 April 1935
Designations
MPC designation (1355) Magoeba
Named after
Magoeba
(South African chief)[2]
1935 HE
main-belt · Hungaria[3][4]
Orbital characteristics[1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc 81.53 yr (29,780 days)
Aphelion 1.9363 AU
Perihelion 1.7709 AU
1.8536 AU
Eccentricity 0.0446
2.52 yr (922 days)
167.86°
0° 23m 26.16s / day
Inclination 22.827°
225.25°
340.30°
Physical characteristics
Dimensions 4.276±0.170 km[5]
4.828±0.094 km[6]
5.96 km (calculated)[4]
2.9712±0.0003 h[7]
2.972±0.002 h[8]
2.975±0.002 h[8]
5.946±0.005 h[9]
5.99±0.05 h[10]
31.65±0.05 h[9]
32.9±0.1 h[11]
0.267±0.095[12]
0.3 (assumed)[4]
0.4663±0.0824[6]
0.582±0.049[5]
B–V = 0.713[1]
U–B = 0.255[1]
Tholen = X[1] · M[13] · E[6] · X[4]
13.02±0.22[14] · 13.05[1][4][6]

1355 Magoeba, provisional designation 1935 HE, is a Hungaria asteroid and a suspected binary from the innermost regions of the asteroid belt, approximately 5 kilometers in diameter. It was discovered on 30 April 1935, by English-born, South African astronomer Cyril Jackson at Johannesburg Observatory in South Africa.[3] It is named for Magoeba, a tribal chief in the South African Transvaal Province.[2]

Description[edit]

Magoeba is a member of the Hungaria family, which forms the innermost dense concentration of asteroids in the Solar System. It orbits the Sun at a distance of 1.8–1.9 AU once every 2 years and 6 months (922 days). Its orbit has an eccentricity of 0.04 and an inclination of 23° with respect to the ecliptic.[1] The first precovery was taken at Nice Observatory just 3 day prior to its official discovery. The body's observation arc begins at Johannesburg the night after its discovery observation.[3]

Between 2006 and 2014, several rotational light-curves[a] of Magoeba were obtained by American astronomer Brian Warner at the CS3–Palmer Divide Observatory (see video in § External links). Light-curve analysis of the photometric observations taken during the asteroid's 2014-apparition gave a rotation period of 2.971 hours with a brightness variation of 0.09 magnitude (U=3).[7] Previously derived periods varied strongly (5.99 and 31.65 hours) with alternative period solutions (U=2-/2/2).[9][10][11] It is now suspected that this discrepancy might be caused by the presence of an asteroid moon that orbits Magoeba with a period of 15.05 hours.[7]

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Magoeba measures 4.276 and 4.828 kilometers in diameter, and its surface has an albedo of 0.582 and 0.466, respectively,[5][6] while a polarimetric study of Hungaria asteroids found a lower albedo of 0.267.[12] The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.30 – a compromise value between 0.4 and 0.2, corresponding to the Hungaria asteroids both as family and orbital group – and calculates a diameter of 5.96 kilometers, based on an absolute magnitude of 13.05.[4]

In the Tholen taxonomy, Magoeba is a X-type asteroid, which can be further divided into the bright E, the metallic M and the carbonaceous P classes, with similar spectra but very different inferred mineralogies.[13] It has both been classified as an E-type asteroid by the WISE/NEOWISE mission, and as a M-type asteroid by a dedicated spectroscopic survey at the Argentinian Lencito Complex, respectively.[6][13]

The minor planet was named for Magoeba, a native chief of the North Transvaal in South Africa.[2] Naming citation was published before November 1977 (M.P.C. 908).[15]

References[edit]

  1. ^ Light-curve plots of (1355) Magoeba from the 2013-observation and from the 2014-observation, published by the Center for Solar System Studies (CS3) in Landers, California.
  1. ^ a b c d e f g "JPL Small-Body Database Browser: 1355 Magoeba (1935 HE)" (2016-11-10 last obs.). Jet Propulsion Laboratory. Retrieved 13 January 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1355) Magoeba. Springer Berlin Heidelberg. p. 110. ISBN 978-3-540-00238-3. Retrieved 13 January 2017. 
  3. ^ a b c "1355 Magoeba (1935 HE)". Minor Planet Center. Retrieved 13 January 2017. 
  4. ^ a b c d e f "LCDB Data for (1355) Magoeba". Asteroid Lightcurve Database (LCDB). Retrieved 13 January 2017. 
  5. ^ a b c 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. Bibcode:2014ApJ...791..121M. arXiv:1406.6645Freely accessible. doi:10.1088/0004-637X/791/2/121. Retrieved 13 January 2017. 
  6. ^ a b c d e f Mainzer, A.; Grav, T.; Masiero, J.; Hand, E.; Bauer, J.; Tholen, D.; et al. (November 2011). "NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results" (PDF). The Astrophysical Journal. 741 (2): 25. Bibcode:2011ApJ...741...90M. arXiv:1109.6407Freely accessible. doi:10.1088/0004-637X/741/2/90. Retrieved 13 January 2017. 
  7. ^ a b c Warner, Brian D. (January 2015). "A Sextet of Main-belt Binary Asteroid Candidates". The Minor Planet Bulletin. 42 (1): 60–66. Bibcode:2015MPBu...42...60W. ISSN 1052-8091. Retrieved 13 January 2017. 
  8. ^ a b Warner, Brian D. (October 2013). "Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2013 May-June". The Minor Planet Bulletin. 40 (4): 208–212. Bibcode:2013MPBu...40..208W. ISSN 1052-8091. Retrieved 13 January 2017. 
  9. ^ a b c Warner, Brian D. (April 2010). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2009 September-December". The Minor Planet Bulletin. 37 (2): 57–64. Bibcode:2010MPBu...37...57W. ISSN 1052-8091. Retrieved 13 January 2017. 
  10. ^ a b Warner, Brian D. (October 2011). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory: 2011 March - July". The Minor Planet Bulletin. 38 (4): 190–195. Bibcode:2011MPBu...38..190W. ISSN 1052-8091. Retrieved 13 January 2017. 
  11. ^ a b Warner, Brian D. (March 2007). "Asteroid Lightcurve Analysis at the Palmer Divide Observatory - June-September 2006". The Minor Planet Bulletin. 34 (1): 8–10. Bibcode:2007MPBu...34....8W. ISSN 1052-8091. Retrieved 13 January 2017. 
  12. ^ a b Gil-Hutton, R.; Lazzaro, D.; Benavidez, P. (June 2007). "Polarimetric observations of Hungaria asteroids". Astronomy and Astrophysics. 468 (3): 1109–1114. Bibcode:2007A&A...468.1109G. doi:10.1051/0004-6361:20077178. Retrieved 13 January 2017. 
  13. ^ a b c Fornasier, S.; Clark, B. E.; Dotto, E. (July 2011). "Spectroscopic survey of X-type asteroids". Icarus. 214 (1): 131–146. Bibcode:2011Icar..214..131F. arXiv:1105.3380Freely accessible. doi:10.1016/j.icarus.2011.04.022. Retrieved 13 January 2017. 
  14. ^ 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. Bibcode:2015Icar..261...34V. arXiv:1506.00762Freely accessible. doi:10.1016/j.icarus.2015.08.007. Retrieved 13 January 2017. 
  15. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 13 January 2017. 

External links[edit]