1185 Nikko, provisional designation 1927 WC, is a stony asteroid from the inner regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 17 November 1927 by Okuro Oikawa at the Tokyo Astronomical Observatory, Japan.[11] The asteroid was named after the Japanese city of Nikkō.[2]

1185 Nikko
Discovery[1]
Discovered byO. Oikawa
Discovery siteTokyo Astronomical Obs. (389)
Discovery date17 November 1927
Designations
(1185) Nikko
Named after
Nikkō (Japanese city)[2]
1927 WC · 1930 SE1
1930 SG1 · 1930 SH1
main-belt · (inner)[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc86.78 yr (31,697 days)
Aphelion2.4744 AU
Perihelion2.0006 AU
2.2375 AU
Eccentricity0.1059
3.35 yr (1,222 days)
280.93°
0° 17m 40.2s / day
Inclination5.7013°
71.904°
1.9614°
Physical characteristics
Dimensions8.347±0.297 km[4]
11.35 km (calculated)[3]
12.56±0.83 km[5]
3.781±0.0326[6]
3.78615±0.00005 h[7]
3.788±0.0326 h[6]
3.7889±0.0004 h[8]
3.79±0.01 h[9]
3.792±0.002 h[8]
0.164±0.023[5]
0.20 (assumed)[3]
0.370±0.041[4]
S (Tholen)[1] · S (SMASS)[1]
S[3]
B–V = 0.923[1]
U–B = 0.514[1]
11.674±0.002 (R)[6] · 11.99±0.33[10] · 12.09[1][3][4][5]

Orbit and classification edit

Nikko orbits the Sun in the inner main-belt at a distance of 2.0–2.5 AU once every 3 years and 4 months (1,222 days). Its orbit has an eccentricity of 0.11 and an inclination of 6° with respect to the ecliptic.[1] Nikko's observation arc begins with its first used observation taken at Johannesburg Observatory in 1930, or 3 years after its official discovery observation at Tokyo.[11]

Physical characteristics edit

In both the Tholen and SMASS taxonomy, Nikko is a common stony S-type asteroid.[1]

Rotation period edit

Between 2004 and 2011, several rotational lightcurves of Nikko were obtained from photometric observations taken by astronomers Laurent Bernasconi,[8] Hiromi and Hiroko Hamanowa,[8] John Menke,[12] Robert Stephens,[9] as well as at the Palomar Transient Factory in California.[6] Lightcurve analysis gave a rotation period between 3.781 and 3.792 hours with a brightness variation between 0.26 and 0.50 magnitude (U=3/3/3/3-/2/2).[3]

Diameter and albedo edit

According to the survey carried out by the Japanese Akari satellite and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Nikko measures 8.347 and 12.56 kilometers in diameter, and its surface has an albedo of 0.370 and 0.164, respectively.[4][5] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.20 and calculates a diameter of 11.35 kilometers with an absolute magnitude of 12.09.[3]

Naming edit

This minor planet was named for the Japanese city of Nikkō, located in the Tochigi Prefecture of central Japan. The tourist resort is known for its Shinto shrine and a UNESCO World Heritage Site Nikkō Tōshō-gū. The official naming citation was published by Paul Herget in The Names of the Minor Planets in 1955 (H 110).[2][13]

References edit

  1. ^ a b c d e f g h i "JPL Small-Body Database Browser: 1185 Nikko (1927 WC)" (2017-07-01 last obs.). Jet Propulsion Laboratory. Retrieved 26 July 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(1185) Nikko". Dictionary of Minor Planet Names – (1185) Nikko. Springer Berlin Heidelberg. p. 99. doi:10.1007/978-3-540-29925-7_1186. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f g "LCDB Data for (1185) Nikko". Asteroid Lightcurve Database (LCDB). Retrieved 12 March 2017.
  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. arXiv:1209.5794. Bibcode:2012ApJ...759L...8M. doi:10.1088/2041-8205/759/1/L8. Retrieved 12 March 2017.
  5. ^ 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. (online, AcuA catalog p. 153)
  6. ^ a b c d 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. Retrieved 12 March 2017.
  7. ^ Hanus, J.; Durech, J.; Broz, M.; Warner, B. D.; Pilcher, F.; Stephens, R.; et al. (June 2011). "A study of asteroid pole-latitude distribution based on an extended set of shape models derived by the lightcurve inversion method". Astronomy & Astrophysics. 530: 16. arXiv:1104.4114. Bibcode:2011A&A...530A.134H. doi:10.1051/0004-6361/201116738. Retrieved 12 March 2017.
  8. ^ a b c d Behrend, Raoul. "Asteroids and comets rotation curves – (1185) Nikko". Geneva Observatory. Retrieved 12 March 2017.
  9. ^ a b Stephens, Robert D. (June 2005). "Rotational periods of 743 Eugenisis, 995 Sternberga, 1185 Nikko 2892 Filipenko, 3144 Brosche, and 3220 Murayama". The Minor Planet Bulletin. 32 (2): 27–28. Bibcode:2005MPBu...32...27S. ISSN 1052-8091. Retrieved 12 March 2017.
  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. Retrieved 12 March 2017.
  11. ^ a b "1185 Nikko (1927 WC)". Minor Planet Center. Retrieved 12 March 2017.
  12. ^ Menke, John (December 2005). "Asteroid lightcurve results from Menke Observatory". The Minor Planet Bulletin. 32 (4): 85–88. Bibcode:2005MPBu...32...85M. ISSN 1052-8091. Retrieved 12 March 2017.
  13. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 12 March 2017.

External links edit