6500 Kodaira, provisional designation 1993 ET, is a highly eccentric, rare-type asteroid and sizable Mars-crosser from the central regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 15 March 1993, by Japanese amateur astronomers Kin Endate and Kazuro Watanabe at Kitami Observatory in eastern Hokkaidō, Japan.[3] It was named for Japanese astronomer Keiichi Kodaira.[2]

6500 Kodaira
Discovery [1]
Discovered byK. Endate
K. Watanabe
Discovery siteKitami Obs.
Discovery date15 March 1993
Designations
(6500) Kodaira
Named after
Keiichi Kodaira
(Japanese astronomer)[2]
1993 ET · 1970 GE1
1973 ST5
Mars-crosser[1][3][4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc47.15 yr (17,222 days)
Aphelion3.9033 AU
Perihelion1.6061 AU
2.7547 AU
Eccentricity0.4170
4.57 yr (1,670 days)
181.45°
0° 12m 56.16s / day
Inclination29.321°
186.12°
255.49°
Physical characteristics
Dimensions9.487±2.081[5]
16.81 km (calculated)[4]
5.3983±0.0026 h[6]
5.3988±0.0002 h[7]
5.400±0.001 h[8]
5.496±0.009 h[9]
0.057 (assumed)[4]
0.151±0.110[5]
SMASS = B[1] · B[4]
12.39±0.21[10] · 12.6[1][4] · 12.640±0.007 (R)[6]

Orbit and classification

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Kodaira orbits the Sun at a distance of 1.6–3.9 AU once every 4 years and 7 months (1,670 days). Its orbit has an eccentricity of 0.42 and an inclination of 29° with respect to the ecliptic.[1]

In April 1970, it was first identified as 1970 GE1 at the Chilean Cerro El Roble Station, extending the body's observation arc by 23 years prior to its official discovery observation at Kitami.[3]

Physical characteristics

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In the SMASS classification, Kodaira is carbonaceous and uncommon B-type asteroid, of which only a few dozen bodies are currently known.[11]

Rotation period

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In October 2014, a rotational lightcurve of Kodaira was obtained from photometric observations by American astronomer Robert Stephens at the Center for Solar System Studies (U81) in California. Lightcurve analysis gave a well-defined rotation period of 5.400 hours with a brightness variation of 0.78 magnitude (U=3).[8]

Previous observations at Montgomery College Observatory (MCO), the Preston Gott and McDonald Observatories, and at the Palomar Transient Factory gave similar periods between 5.398 and 5.496 hours (U=3-/3-/2).[6][7][9]

Diameter and albedo

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According to first-year results from the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Kodaira measures 9.5 kilometers in diameter and its surface has an albedo of 0.15,[5] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 16.8 kilometers with an absolute magnitude of 12.6.[4]

Naming

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This minor planet was named after Keiichi Kodaira (born 1937), Japanese astronomer and director of NAOJ, whose interests lie in astrophysics and galactic physics.[2]

In the 1980s, Kodaira was head of IAU's commission of Theory of Stellar Atmospheres (comm. 36). He was also instrumental for the completion of the Subaru Telescope project, of which he was the scientific director since its inception.[2] The approved naming citation was published by the Minor Planet Center on 1 June 1996 (M.P.C. 27331).[12]

References

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  1. ^ a b c d e f "JPL Small-Body Database Browser: 6500 Kodaira (1993 ET)" (2017-06-05 last obs.). Jet Propulsion Laboratory. Retrieved 21 June 2017.
  2. ^ a b c d Schmadel, Lutz D. (2007). "(6500) Kodaira". Dictionary of Minor Planet Names – (6500) Kodaira. Springer Berlin Heidelberg. p. 537. doi:10.1007/978-3-540-29925-7_5911. ISBN 978-3-540-00238-3.
  3. ^ a b c "6500 Kodaira (1993 ET)". Minor Planet Center. Retrieved 2 May 2016.
  4. ^ a b c d e f "LCDB Data for (6500) Kodaira". Asteroid Lightcurve Database (LCDB). Retrieved 2 May 2016.
  5. ^ a b c 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. S2CID 9341381. Retrieved 26 October 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. arXiv:1504.04041. Bibcode:2015AJ....150...75W. doi:10.1088/0004-6256/150/3/75. S2CID 8342929. Retrieved 2 May 2016.
  7. ^ a b Clark, Maurice (October 2011). "Asteroid Lightcurves from the Preston Gott and McDonald Observatories". The Minor Planet Bulletin. 38 (4): 187–189. Bibcode:2011MPBu...38..187C. ISSN 1052-8091. Retrieved 2 May 2016.
  8. ^ a b Stephens, Robert D. (April 2015). "Asteroids Observed from CS3: 2014 October - December". The Minor Planet Bulletin. 42 (2): 104–106. Bibcode:2015MPBu...42..104S. ISSN 1052-8091. Retrieved 2 May 2016.
  9. ^ a b Clark, Maurice (March 2007). "Lightcurve Results for 1318 Nerina, 222 Lermontov 3015 Candy, 3089 Oujianquan, 3155 Lee, 6410 Fujiwara, 6500 Kodaira, (8290) 1992 NP, 9566 Rykhlova, (42923) 1999 SR18, and 2001 FY". The Minor Planet Bulletin. 34 (1): 19–22. Bibcode:2007MPBu...34...19C. ISSN 1052-8091. Retrieved 2 May 2016.
  10. ^ 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. S2CID 53493339. Retrieved 2 May 2016.
  11. ^ "JPL Small-Body Database Search Engine: spec. type: B (SMASSII)". JPL Solar System Dynamics. Retrieved 1 January 2006.
  12. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 2 May 2016.
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