1206 Numerowia

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1206 Numerowia
Discovery [1]
Discovered by K. Reinmuth
Discovery site Heidelberg Obs.
Discovery date 18 October 1931
MPC designation (1206) Numerowia
Named after
Boris Numerov
(Russian astronomer)[2]
1931 UH · 1974 QE
1974 TY1
main-belt · (outer)[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 85.63 yr (31,276 days)
Aphelion 3.0180 AU
Perihelion 2.7123 AU
2.8651 AU
Eccentricity 0.0533
4.85 yr (1,771 days)
0° 12m 11.52s / day
Inclination 13.003°
Physical characteristics
Dimensions 14.173±0.092 km[4]
14.534±0.264 km[5]
15.63±1.09 km[6]
27.90 km (calculated)[3]
4.7743±0.0013 h[7]
4.77529±0.00001 h[8]
0.057 (assumed)[3]
11.5[1][3] · 11.80[4][6]

1206 Numerowia, provisional designation 1931 UH, is an asteroid from the outer region of the asteroid belt, approximately 15 kilometers in diameter. It was discovered by German astronomer Karl Reinmuth at Heidelberg Observatory in southwest Germany on 18 October 1931, and named after Russian astronomer Boris Numerov.[2][9]

Orbit and classification[edit]

Numerowia orbits the Sun in the outer main-belt at a distance of 2.7–3.0 AU once every 4 years and 10 months (1,771 days). Its orbit has an eccentricity of 0.05 and an inclination of 13° with respect to the ecliptic.[1] The asteroid's observation arc begins at Heidelberg four days after its official discovery observation.[9]

Physical characteristics[edit]

Rotation period and poles[edit]

In February 2006, a rotational lightcurve of Numerowia was obtained from photometric observations by astronomer Lawrence Molnar and colleges at the Calvin–Rehoboth Observatory in New Mexico, United States. Lightcurve analysis gave a well-defined rotation period of 4.7743 hours with a high brightness variation of 0.63 magnitude (U=3), indicating that the body has a non-spheroidal shape.[7]

A 2016-published lightcurve, using modeled photometric data from the Lowell Photometric Database (LPD), gave a concurring period of 4.77529 hours (U=n.a.), as well as two spin axis of (64.0°, −50.0°) and (271.0°, −69.0°) in ecliptic coordinates (λ, β).[8]

Diameter and albedo[edit]

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Numerowia measures between 14.173 and 15.63 kilometers in diameter and its surface has an albedo between 0.141 and 0.168.[4][5][6]

The Collaborative Asteroid Lightcurve Link assumes a standard albedo for C-type asteroid of 0.057 and consequently calculates a larger diameter of 27.90 kilometers using an absolute magnitude of 11.5.[3]


This minor planet was named after Russian astronomer and geophysicist Boris Numerov (1891–1941), founder and director of the Institute for Theoretical Astronomy in Leningrad, who was executed for espionage by the Soviet Union in 1941. The accusation was based on the fact that a German had named the asteroid after him.[2] In 1957, his memory was rehabilitated.[10] The lunar crater Numerov was also named in his honour. The official naming citation was published by Paul Herget in The Names of the Minor Planets in 1955 (H 112).[2]


  1. ^ a b c d "JPL Small-Body Database Browser: 1206 Numerowia (1931 UH)" (2017-06-04 last obs.). Jet Propulsion Laboratory. Retrieved 5 August 2017. 
  2. ^ a b c d Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (1206) Numerowia. Springer Berlin Heidelberg. p. 101. ISBN 978-3-540-00238-3. Retrieved 5 August 2017. 
  3. ^ a b c d e f "LCDB Data for (1206) Numerowia". Asteroid Lightcurve Database (LCDB). Retrieved 5 August 2017. 
  4. ^ 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" (PDF). The Astrophysical Journal. 741 (2): 25. arXiv:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 5 August 2017. 
  5. ^ 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:1109.4096Freely accessible. Bibcode:2011ApJ...741...68M. doi:10.1088/0004-637X/741/2/68. Retrieved 5 August 2017. 
  6. ^ 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 5 August 2017. 
  7. ^ a b Molnar, Lawrence A.; Haegert, Melissa, J.; Beaumont, Christopher N.; Block, Marjorie J.; Brom, Timothy H.; Butler, Andrew R.; et al. (March 2008). "Lightcurve Analysis of a Magnitude Limited Asteroid Sample". The Minor Planet Bulletin. 35 (1): 9–12. Bibcode:2008MPBu...35....9M. ISSN 1052-8091. Retrieved 5 August 2017. 
  8. ^ a b Durech, J.; Hanus, J.; Oszkiewicz, D.; Vanco, R. (March 2016). "Asteroid models from the Lowell photometric database". Astronomy and Astrophysics. 587: 6. arXiv:1601.02909Freely accessible. Bibcode:2016A&A...587A..48D. doi:10.1051/0004-6361/201527573. Retrieved 5 August 2017. 
  9. ^ a b "1206 Numerowia (1931 UH)". Minor Planet Center. Retrieved 5 August 2017. 
  10. ^ "Columbia University Computing History–A Chronology of Computing at Columbia University". Columbia University. 30 January 2017. Retrieved 5 August 2017. 

External links[edit]