11133 Kumotori

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
11133 Kumotori
Discovery [1]
Discovered by T. Kobayashi
Discovery site Ōizumi Obs.
Discovery date 2 December 1996
MPC designation (11133) Kumotori
Named after
Mount Kumotori
(Japanese mountain)[2]
1996 XY
main-belt · (outer)[3]
background [4]
Orbital characteristics[1]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc 28.27 yr (10,324 d)
Aphelion 2.9313 AU
Perihelion 2.6210 AU
2.7762 AU
Eccentricity 0.0559
4.63 yr (1,690 d)
0° 12m 47.16s / day
Inclination 10.689°
Physical characteristics
Mean diameter
8.96 km (calculated)[3]
4.634±0.0005 h[5]
0.057 (assumed)[3]
L[6] · C (assumed)[3]
13.517±0.003 (R)[5]
13.6[1] · 13.97[3]

11133 Kumotori, provisional designation 1996 XY, is a background asteroid from the central regions of the asteroid belt, approximately 9 kilometers (6 miles) in diameter. It was discovered on 2 December 1996, by Japanese amateur astronomer Takao Kobayashi at his Ōizumi Observatory. The asteroid was named after Mount Kumotori near Tokyo.[2] It has a rotation period of 4.6 hours.[3]

Orbit and classification[edit]

Kumotori is a non-family asteroid from the main belt's background population.[4] It orbits the Sun in the central main-belt at a distance of 2.6–2.9 AU once every 4 years and 8 months (1,690 days; semi-major axis of 2.786 AU). Its orbit has an eccentricity of 0.06 and an inclination of 11° with respect to the ecliptic.[1] The asteroid was first observed at Palomar Observatory in March 1989. The body's observation arc begins with its official discovery observation at Oizumi.[2]

Physical characteristics[edit]

Kumotori has been characterized as a rare L-type asteroid by Pan-STARRS' survey.[6] It is also assumed to be a carbonaceous C-type asteroid.[3]

Rotation period[edit]

In April 2012, a rotational lightcurve of Kumotori was obtained from photometric observations in the R-band by astronomers at the Palomar Transient Factory in California. Lightcurve analysis gave a rotation period of 4.634 hours with a brightness amplitude of 0.33 magnitude (U=2).[5]

Diameter and albedo[edit]

The Collaborative Asteroid Lightcurve Link assumes an albedo for a carbonaceous asteroid of 0.057 and calculates a diameter of 8.96 kilometers based on an absolute magnitude of 13.97.[3]


This minor planet was named after Mount Kumotori (雲取山 Kumotori-san). With an altitude of 2,017 metres (6,617 ft), it is the highest peak in the Tokyo metropolitan area, located at the boundary between Tokyo and Saitama and considered to be one of the 100 most celebrated mountains of Japan.[2] The official naming citation was published by the Minor Planet Center on 9 November 2003 (M.P.C. 50251).[7]


  1. ^ a b c d "JPL Small-Body Database Browser: 11133 Kumotori (1996 XY)" (2017-07-05 last obs.). Jet Propulsion Laboratory. Retrieved 2 March 2018. 
  2. ^ a b c d "11133 Kumotori (1996 XY)". Minor Planet Center. Retrieved 2 March 2018. 
  3. ^ a b c d e f g h "LCDB Data for (11133) Kumotori". Asteroid Lightcurve Database (LCDB). Retrieved 2 March 2018. 
  4. ^ a b "Small Bodies Data Ferret". Nesvorny HCM Asteroid Families V3.0. Retrieved 2 March 2018. 
  5. ^ 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. arXiv:1504.04041Freely accessible. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. Retrieved 2 March 2018. 
  6. ^ a b c 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:1506.00762Freely accessible. Bibcode:2015Icar..261...34V. doi:10.1016/j.icarus.2015.08.007. Retrieved 2 March 2018. 
  7. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 2 March 2018. 

External links[edit]