1428 Mombasa, provisional designation 1937 NO, is a dark asteroid from the middle region of the asteroid belt, approximately 56 kilometers in diameter.

1428 Mombasa
Discovery [1]
Discovered byC. Jackson
Discovery siteJohannesburg Obs.
Discovery date5 July 1937
MPC designation(1428) Mombasa
Named after
Mombasa (city, port)[2]
1937 NO · 1933 WO
1949 FA · 1957 YZ
main-belt · (middle)
Orbital characteristics[1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc82.74 yr (30,219 days)
Aphelion3.2039 AU
Perihelion2.4154 AU
2.8096 AU
4.71 yr (1,720 days)
0° 12m 33.48s / day
Physical characteristics
Dimensions52.464±0.268 km[3]
53.35±13.28 km[4]
55.34±0.70 km[5]
56.63±2.0 km[6]
56.83 km (derived)[7]
57.59±19.41 km[8]
62.45±0.73 km[9]
127.203±29.18 km[10]
16.67±0.01 h[a]
17.12±0.01 h[11]
17.6±0.2 h[12]
0.0415 (derived)[7]
SMASS = Xc [1] · P[10] · C[7]
9.95±0.74[13] · 10.20[8][9] · 10.27[4] · 10.3[1][7] · 10.9[5][6][10]

It was discovered on 5 July 1937, by English-born South African astronomer Cyril Jackson at Johannesburg Observatory, South Africa, and later named after Mombasa, Kenya.[2][14]

Orbit and classificationEdit

Mombasa orbits the Sun at a distance of 2.4–3.2 AU once every 4 years and 9 months (1,720 days). Its orbit has an eccentricity of 0.14 and an inclination of 17° with respect to the ecliptic.[1] Mombasa was first identified as 1933 WO at Lowell Observatory, extending the body's observation arc by 4 years prior to its official discovery at Johannesburg.[14]

Physical characteristicsEdit

Rotation periodEdit

American astronomer Robert Stephens obtained a rotational lightcurve of Mombasa in June 2012. Light-curve analysis gave a rotation period of 16.67 hours with a brightness variation of 0.16 magnitude (U=2+).[a] Previous lightcurves were obtained by French amateur astronomer René Roy in February 2006 (17.6 hours, Δ0.15 mag; U=2),[12] as well as by Scot Hawkins and Richard Ditteon at Oakley Observatory in May 2007 (17.12 hours, Δ0.25 mag; U=2).[11]

Spectral type, diameter and albedoEdit

On the SMASS taxonomic scheme, Mombasa is a Xc-type, an intermediate between the carbonaceous C and X-type, while it is also described as a darker P-type asteroid.[10] According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Mombasa measures between 52.46 and 62.45 kilometers in diameter, ignoring a preliminary result of 127 km,[10] and its surface has an albedo of 0.025 and 0.06.[3][4][5][6][8][9] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0415 and a diameter of 56.83 kilometers with an absolute magnitude of 10.3.[7]


This minor planet was named after Mombasa, chief-port and second largest city of Kenya on the coast of East Africa.[2] The official naming citation was published by the Minor Planet Center in April 1953 (M.P.C. 909).[15]


  1. ^ a b Stephens (2012) web: rotation period 16.67±0.01 hours with a brightness amplitude of 0.16 mag. Notes: "A half-period of 8.38 h cannot be formally excluded". Summary figures at Collaborative Asteroid Lightcurve Link (CALL) for (1428) Mombasa


  1. ^ a b c d e "JPL Small-Body Database Browser: 1428 Mombasa (1937 NO)" (2016-08-13 last obs.). Jet Propulsion Laboratory. Retrieved 6 January 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(1428) Mombasa". Dictionary of Minor Planet Names – (1428) Mombasa. Springer Berlin Heidelberg. p. 115. doi:10.1007/978-3-540-29925-7_1429. ISBN 978-3-540-00238-3.
  3. ^ 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 6 January 2017.
  4. ^ 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. Retrieved 6 January 2017.
  5. ^ 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. Retrieved 17 October 2019. (online, AcuA catalog p. 153)
  6. ^ 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.
  7. ^ a b c d e "LCDB Data for (1428) Mombasa". Asteroid Lightcurve Database (LCDB). Retrieved 6 January 2017.
  8. ^ a b c d Nugent, C. R.; Mainzer, A.; Masiero, J.; Bauer, J.; Cutri, R. M.; Grav, T.; et al. (December 2015). "NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos". The Astrophysical Journal. 814 (2): 13. arXiv:1509.02522. Bibcode:2015ApJ...814..117N. doi:10.1088/0004-637X/814/2/117. Retrieved 6 January 2017.
  9. ^ 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 6 January 2017.
  10. ^ 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". The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
  11. ^ a b Hawkins, Scot; Ditteon, Richard (March 2008). "Asteroid Lightcurve Analysis at the Oakley Observatory - May 2007". The Minor Planet Bulletin. 35 (1): 1–4. Bibcode:2008MPBu...35....1H. ISSN 1052-8091. Retrieved 6 January 2017.
  12. ^ a b Behrend, Raoul. "Asteroids and comets rotation curves – (1428) Mombasa". Geneva Observatory. Retrieved 6 January 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. Retrieved 6 January 2017.
  14. ^ a b "1428 Mombasa (1937 NO)". Minor Planet Center. Retrieved 6 January 2017.
  15. ^ 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.

External linksEdit