3133 Sendai

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3133 Sendai
Discovery [1]
Discovered by A. Kopff
Discovery site Heidelberg Obs.
Discovery date 4 October 1907
MPC designation (3133) Sendai
Named after
Sendai (Japanese city)[2]
A907 TC · 1968 TO
1973 DN · 1981 UX
1984 QG1 · A907 XA
main-belt · Flora[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc 109.19 yr (39,882 days)
Aphelion 2.5314 AU
Perihelion 1.8299 AU
2.1806 AU
Eccentricity 0.1608
3.22 yr (1,176 days)
0° 18m 21.96s / day
Inclination 6.5666°
Physical characteristics
Dimensions 7.25±0.30 km[4]
7.47 km (calculated)[3]
8.323±0.066 km[5]
5.7491±0.0008 h[6]
5.776±0.005 h[a]
0.24 (assumed)[3]
12.8[1][3] · 12.7[5] · 12.7[4] · 12.522±0.001 (R)[6] · 12.92±0.21[7]

3133 Sendai, provisional designation A907 TC, is a stony Flora asteroid from the inner regions of the asteroid belt, approximately 8 kilometers in diameter. It was discovered on 4 October 1907, by German astronomer August Kopff at Heidelberg Observatory in southwest Germany.[8] The asteroid was named for the Japanese city of Sendai.[2]

Orbit and classification[edit]

Sendai is a member of the Flora family, one of the largest groups of stony asteroids in the main-belt. It orbits the Sun in the inner main-belt at a distance of 1.8–2.5 AU once every 3 years and 3 months (1,176 days). Its orbit has an eccentricity of 0.16 and an inclination of 7° with respect to the ecliptic.[1]

Physical characteristics[edit]

Sendai has been characterized as a stony S-type asteroid.[3]

Diameter and albedo[edit]

According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer and its extended NEOWISE mission, the asteroid's surface has an albedo of 0.21 and 0.31, with a diameter of 8.3 and 7.3 kilometers, respectively.[4][5] The Collaborative Asteroid Lightcurve Link assumes an intermediate albedo of 0.24 – which derives from 8 Flora, the largest member and namesake of this orbital family – and calculates a concurring diameter of 7.5 kilometers.[3]


In 2010, two rotational lightcurves were obtained by amateur astronomer Ralph Megna at Goat Mountain Astronomical Research Station (G79), and by the U.S. Palomar Transient Factory in California. The concurring lightcurves showed a rotation period of 5.776±0.005 and 5.7491±0.0008 hours, respectively (U=3-/2).[a][6]


This minor planet was named for the second largest city north of Tokyo, Sendai (pop. 1 million), location of the Tōhoku University. It is the home of the Sendai Astronomical Observatory, which was founded in 1955, on appeal by the Sendai Amateur Astronomical Association. The observatory has discovered several minor planets.[2] The official naming citation was published by the Minor Planet Center on 29 September 1985 (M.P.C. 10045).[9]


  1. ^ a b Megna (2011) web: rotation period 5.776±0.005 hours with a brightness amplitude of 0.19 mag. Light-curve chart at Ralph Megna's website and summary figures for (3133) Sendai at Collaborative Asteroid Lightcurve Link (CALL).


  1. ^ a b c d "JPL Small-Body Database Browser: 3133 Sendai (A907 TC)" (2016-12-12 last obs.). Jet Propulsion Laboratory. Retrieved 16 June 2017. 
  2. ^ a b c Schmadel, Lutz D. (2007). Dictionary of Minor Planet Names – (3133) Sendai. Springer Berlin Heidelberg. p. 259. ISBN 978-3-540-00238-3. Retrieved 27 April 2016. 
  3. ^ a b c d e f g "LCDB Data for (3133) Sendai". Asteroid Lightcurve Database (LCDB). Retrieved 27 April 2016. 
  4. ^ 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. Bibcode:2012ApJ...759L...8M. arXiv:1209.5794Freely accessible. doi:10.1088/2041-8205/759/1/L8. Retrieved 11 January 2016. 
  5. ^ 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. Bibcode:2011ApJ...741...90M. arXiv:1109.6407Freely accessible. doi:10.1088/0004-637X/741/2/90. Retrieved 27 April 2016. 
  6. ^ a b c Waszczak, Adam; Chang, Chan-Kao; Ofek, Eran O.; Laher, Russ; Masci, Frank; Levitan, David; et al. (September 2015). "Asteroid Light Curves from the Palomar Transient Factory Survey: Rotation Periods and Phase Functions from Sparse Photometry". The Astronomical Journal. 150 (3): 35. Bibcode:2015AJ....150...75W. arXiv:1504.04041Freely accessible. doi:10.1088/0004-6256/150/3/75. Retrieved 27 April 2016. 
  7. ^ 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 27 April 2016. 
  8. ^ "3133 Sendai (A907 TC)". Minor Planet Center. Retrieved 27 April 2016. 
  9. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 27 April 2016. 

External links[edit]