1468 Zomba
Discovery[1]
Discovered byC. Jackson
Discovery siteJohannesburg Obs.
Discovery date23 July 1938
Designations
(1468) Zomba
Named after
Zomba (Malawian city)[2]
1938 PA
Mars-crosser[1][3][4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc78.47 yr (28,660 days)
Aphelion2.7913 AU
Perihelion1.5998 AU
2.1956 AU
Eccentricity0.2713
3.25 yr (1,188 days)
95.275°
0° 18m 10.8s / day
Inclination9.9388°
308.93°
23.188°
Physical characteristics
Dimensions6.97±1.39 km[5]
8.57 km (calculated)[4]
2.769±0.005 h[6][lower-alpha 1]
2.77 h[7]
2.772±0.006 h[8]
2.773±0.001 h[9]
0.20 (assumed)[4]
0.302±0.121[5]
Q[10] · S (assumed)[4]
12.70[1][4][5] · 13.05±0.45[10]

    1468 Zomba, provisional designation 1938 PA, is a stony asteroid and large Mars-crosser near the innermost regions of the asteroid belt, approximately 7 kilometers in diameter. Discovered by Cyril Jackson at Johannesburg Observatory in 1938, the asteroid was named after the city of Zomba in the Republic of Malawi.[3]

    Discovery

    Zomba was discovered on 23 July 1938, by South African astronomer Cyril Jackson at the Union Observatory in Johannesburg, South Africa.[3] It was independently discovered by French astronomer Louis Boyer at the Algiers Observatory, Algeria, on 2 August 1938,[2] who first announce the asteroid's discovery.[1] The Minor Planet Center (MPC) only recognizes the first discoverer.[3]

    Orbit and classification

    Zomba is a Mars-crossing asteroid, a dynamically unstable group between the main belt and the near-Earth populations, crossing the orbit of Mars at 1.666 AU. It orbits the Sun at a distance of 1.6–2.8 AU once every 3 years and 3 months (1,188 days). Its orbit has an eccentricity of 0.27 and an inclination of 10° with respect to the ecliptic.[1] The body's observation arc begins with its official discovery observation at Johannesburg.[3]

    Physical characteristics

    Zomba has been characterized as a Q-type asteroid by Pan-STARRS photometric survey.[10] The Lightcurve Data Base assumes it to be a common S-type asteroid.[4]

    Rotation period

    Several rotational lightcurves of Zomba have been obtained from photometric observations. Lightcurve analysis gave a consolidated rotation period of 2.773 hours with a brightness amplitude between 0.3 and 0.36 magnitude (U=3-/2/3/3).[6][7][8][9][lower-alpha 1]

    Diameter and albedo

    According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Zomba measures 6.97 kilometers in diameter and its surface has an albedo of 0.302,[5] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 8.57 kilometers based on an absolute magnitude of 12.7.[4]

    This makes Zomba one of the largest mid-sized Mars-crossing asteroids comparable with 1065 Amundsenia (9.75 km), 1139 Atami (9.35 km), 1474 Beira (8.73 km), 1011 Laodamia (7.39 km), 1727 Mette (est 9 km), 1131 Porzia (7.13 km), 1235 Schorria (est. 9 km), 985 Rosina (8.18 km) and 1310 Villigera (15.24 km), but far smaller than the largest members of this dynamical group, namely, 132 Aethra, 323 Brucia, 1508 Kemi, 2204 Lyyli and 512 Taurinensis, which are all larger than 20 kilometers in diameter.

    Naming

    This minor planet was named after the town of Zomba in the Republic of Malawi, known as Nyasaland, a British protectorate, at the time of naming. The official naming citation was published by the Minor Planet Center in April 1953 (M.P.C. 909).[11]

    Notes

    1. 1 2 Lightcurve plot of (1468) Zomba, Brian Warner (2015),Palmer Divide Station, California. Rotation period 2.769±0.005 hours with a brightness amplitude of 0.33 mag. Quality code of 3-ä. Summary figures at the LCDB

    References

    1. 1 2 3 4 5 6 "JPL Small-Body Database Browser: 1468 Zomba (1938 PA)" (2017-01-09 last obs.). Jet Propulsion Laboratory. Retrieved 20 October 2017.
    2. 1 2 Schmadel, Lutz D. (2007). "(1468) Zomba". Dictionary of Minor Planet Names. Springer Berlin Heidelberg. p. 117. doi:10.1007/978-3-540-29925-7_1469. ISBN 978-3-540-00238-3.
    3. 1 2 3 4 5 "1468 Zomba (1938 PA)". Minor Planet Center. Retrieved 20 October 2017.
    4. 1 2 3 4 5 6 7 "LCDB Data for (1468) Zomba". Asteroid Lightcurve Database (LCDB). Retrieved 20 October 2017.
    5. 1 2 3 4 Alí-Lagoa, V.; Delbo', M. (July 2017). "Sizes and albedos of Mars-crossing asteroids from WISE/NEOWISE data" (PDF). Astronomy and Astrophysics. 603: 8. arXiv:1705.10263. Bibcode:2017A&A...603A..55A. doi:10.1051/0004-6361/201629917. Retrieved 20 October 2017.
    6. 1 2 Warner, Brian D. (July 2015). "Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2014 December - 2015 March". The Minor Planet Bulletin. 42 (3): 167–172. Bibcode:2015MPBu...42..167W. ISSN 1052-8091. Retrieved 20 October 2017.
    7. 1 2 Wisniewski, W. Z.; McMillan, R. S. (May 1987). "Differential CCD photometry of faint asteroids in crowded star fields and nonphotometric sky conditions". Astronomical Journal. 93: 1264–1267. Bibcode:1987AJ.....93.1264W. doi:10.1086/114408. ISSN 0004-6256. Retrieved 20 October 2017.
    8. 1 2 Benishek, Vladimir (April 2014). "Rotation Period Determination for 1425 Tuorla, 1468 Zomba, 1486 Marilyn, 2112 Ulyanov, and (101158) 2000 OL". The Minor Planet Bulletin. 41 (2): 126–127. Bibcode:2014MPBu...41..126B. ISSN 1052-8091. Retrieved 20 October 2017.
    9. 1 2 Alkema, Michael S. (January 2014). "Asteroid Lightcurve Analysis at Elephant Head Observatory: 2013 August- October". The Minor Planet Bulletin. 41 (1): 40. Bibcode:2014MPBu...41...40A. ISSN 1052-8091. Retrieved 20 October 2017.
    10. 1 2 3 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. Retrieved 20 October 2017.
    11. ↑ Schmadel, Lutz D. "Appendix – Publication Dates of the MPCs". Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008). Springer Berlin Heidelberg. p. 221. doi:10.1007/978-3-642-01965-4. ISBN 978-3-642-01964-7.
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