5357 Sekiguchi

5357 Sekiguchi
Discovery [1]
Discovered by T. Fujii
K. Watanabe
Discovery site Kitami Obs.
Discovery date 2 March 1992
Designations
MPC designation 5357 Sekiguchi
Named after
 Tomohiko Sekiguch
(astronomer)[2]
1992 EL · 1969 TB4
1971 BE3 · 1981 BH
1990 VJ4 · 1990 WU13
main-belt · (outer)[3]
Orbital characteristics [1]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc 65.89 yr (24,066 days)
Aphelion 3.2981 AU
Perihelion 2.6792 AU
2.9886 AU
Eccentricity 0.1035
5.17 yr (1,887 days)
359.2797°
0° 11m 26.88s / day
Inclination 9.0832°
301.9724°
116.8125°
Physical characteristics
Dimensions 15.19±1.13 km[4]
14.281±0.193 km[5]
14.52±0.65 km[6]
25.44 km (calculated)[3]
5.41±0.01 h[7]
5.4048±0.0011 h[8]
5.4100±0.0011 h[8]
0.334±0.052[4]
0.3829±0.0259[5]
0.192±0.032[6]
0.057 (assumed)[3]
C [3]
11.7[1][3]
10.9[4][5]
11.60[6]
11.66±0.17[9]
11.719±0.003 (R)[8]
11.624±0.002 (R)[8]

    5357 Sekiguchi, provisional designation 1992 EL, is an asteroid from the outer region of the asteroid belt, approximately 15 kilometers in diameter. It was discovered on 2 March 1992, by Japanese amateur astronomers Tetsuya Fujii and Kazuro Watanabe at the Kitami Observatory in eastern Hokkaidō, Japan.[2]

    The asteroid orbits the Sun at a distance of 2.7–3.3 AU once every 5 years and 2 months (1,887 days). Its orbit has an eccentricity of 0.10 and an inclination of 9° with respect to the plane of the ecliptic.[1] The first precovery was obtained at Goethe Link Observatory in 1950, extending the asteroid's observation arc by 42 years prior to its discovery.[2]

    A rotational light-curve of this asteroid was obtained by French astronomers René Roy and Laurent Bernasconi from photometric observations made in October 2005. It showed a rotation period of 5.41±0.01 hours with a brightness variation of 0.72 in magnitude (U=3).[7] In October 2010 and November 2011, two more light-curves were obtained at the U.S. Palomar Transient Factory, rendering a period of 5.4048 and 5.4100 hours with an amplitude of 0.58 and 0.27 in magnitude, respectively (U=2/2).[8]

    According to the surveys carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its NEOWISE mission, the asteroid measures between 14.3 and 15.2 kilometers in diameter.[4][5][6] However, the Collaborative Asteroid Lightcurve Link (CALL) calculates a much larger diameter of 25.4 kilometers.[3] This is due to strongly divergent albedos, as the lower the reflectivity (albedo), the larger a body's diameter. While CALL assumes the body's surface to be of a carbonaceous composition, and classifies it as a dark C-type asteroid with a correspondingly low albedo of 0.057, the space-based surveys find higher albedos of 0.19, 0.33 and 0.38, respectively.

    The minor planet was named in honor of Japanese astronomer Tomohiko Sekiguchi (b. 1970), associate professor at Hokkaido University. From 1998 to 2001, he had been observing minor planets at the European Southern Observatory.[2] Naming citation was published on 6 April 2012 (M.P.C. 79102).[10]

    References

    1. 1 2 3 4 "JPL Small-Body Database Browser: 5357 Sekiguchi (1992 EL)" (2016-01-02 last obs.). Jet Propulsion Laboratory. Retrieved 3 May 2016.
    2. 1 2 3 4 "5357 Sekiguchi (1992 EL)". Minor Planet Center. Retrieved 3 May 2016.
    3. 1 2 3 4 5 6 "LCDB Data for (5357) Sekiguchi". Asteroid Lightcurve Database (LCDB). Retrieved 3 May 2016.
    4. 1 2 3 4 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 3 May 2016.
    5. 1 2 3 4 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:1109.6407Freely accessible. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90. Retrieved 3 May 2016.
    6. 1 2 3 4 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:1209.5794Freely accessible. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 3 May 2016.
    7. 1 2 Behrend, Raoul. "Asteroids and comets rotation curves – (5357) Sekiguchi". Geneva Observatory. Retrieved 3 May 2016.
    8. 1 2 3 4 5 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 3 May 2016.
    9. ↑ 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 3 May 2016.
    10. ↑ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 3 May 2016.

    External links

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