5692 Shirao, provisional designation 1992 FR, is a stony Eunomia asteroid from the middle region of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 23 March 1992, by Japanese amateur astronomers Kin Endate and Kazuro Watanabe at Kitami Observatory, Hokkaidō, Japan.[10] The asteroid was later named for Japanese geologist and astrophotographer Motomaro Shirao.[2]

5692 Shirao
Discovery [1]
Discovered byK. Endate
K. Watanabe
Discovery siteKitami Obs.
Discovery date23 March 1992
Designations
(5692) Shirao
Named after
Motomaro Shirao
(geologist, photographer)[2]
1992 FR · 1949 KK
1966 FO · 1966 FS
1970 CH · 1976 SN2
1979 HT2 · 1979 HV1
1985 UW2 · 1989 SO9
main-belt · Eunomia[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc67.83 yr (24,776 days)
Aphelion3.1373 AU
Perihelion2.1723 AU
2.6548 AU
Eccentricity0.1818
4.33 yr (1,580 days)
287.13°
0° 13m 40.44s / day
Inclination11.931°
181.78°
44.251°
Physical characteristics
Dimensions9.17 km (calculated)[3]
9.548±0.155[4]
9.75±0.30 km[5]
9.811±0.063 km[6]
2.886±0.002 h[7]
2.8878±0.0004 h[a]
2.90±0.02 h (ii)[8]
0.21 (assumed)[3]
0.2218±0.0290[6]
0.223±0.030[4][5]
S[3][9]
12.3[5][6] · 12.47±0.25[9] · 12.5[1][3]

Orbit and classification edit

Shirao is a member of the Eunomia family, a large group of stony asteroids and the most prominent family in the intermediate main-belt. It orbits the Sun in the central main-belt at a distance of 2.2–3.1 AU once every 4 years and 4 months (1,580 days). Its orbit has an eccentricity of 0.18 and an inclination of 12° with respect to the ecliptic.[1]

In 1949, it was first identified as 1949 KK at Goethe Link Observatory. The body's observation arc begins in 1955, with a precovery at Palomar Observatory, 37 years prior to its official discovery observation at Kitami.[10]

Physical characteristics edit

Rotation period edit

In June 2014, a rotational lightcurve of Shirao was obtained from photometric observations made by American astronomer Brian Warner at his Palmer Divide Observatory (716) in Colorado. It gave a well-defined rotation period of 2.8878 hours with a brightness variation of 0.16 magnitude (U=3).[a]

Previous lightcurves were obtained by French astronomer René Roy (2.90 hours, Δ 0.13 mag, U=2) in June 2001,[8] by American astronomer Donald P. Pray (2.886 hours, Δ 0.12 mag, U=2) in March 2005,[7] and by astronomers Dominique Suys, Hugo Riemis and Jan Vantomme (2.90 hours, Δ 0.15 mag, U=2+) in September 2006.[3][8]

Diameter and albedo edit

According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer and its subsequent NEOWISE mission, Shirao measures between 9.5 and 9.8 kilometers in diameter and its surface has an albedo of 0.22,[4][5][6] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo of 0.21 – derived from 15 Eunomia, the largest member and namesake of this asteroid family – and calculates a diameter of 9.2 kilometers.[3]

Naming edit

This minor planet was named after Motomaro Shirao (born 1953), a Japanese geologist and astrophotographer, who is known for his photographs of volcanoes and lunar geological features.[2] The official naming citation was published by the Minor Planet Center on 4 April 1996 (M.P.C. 26930).[11]

Notes edit

  1. ^ a b Warner (2014l) web: rotation period 2.8878±0.0004 hours with a brightness amplitude of 0.16 mag. Summary figures for (5692) Shirao at Collaborative Asteroid Lightcurve Link (CALL) and (2014MPBu...41..235P)

References edit

  1. ^ a b c d "JPL Small-Body Database Browser: 5692 Shirao (1992 FR)" (2017-03-29 last obs.). Jet Propulsion Laboratory. Retrieved 21 June 2017.
  2. ^ a b c Schmadel, Lutz D. (2007). "(5692) Shirao". Dictionary of Minor Planet Names – (5692) Shirao. Springer Berlin Heidelberg. p. 482. doi:10.1007/978-3-540-29925-7_5385. ISBN 978-3-540-00238-3.
  3. ^ a b c d e f g "LCDB Data for (5692) Shirao". Asteroid Lightcurve Database (LCDB). Retrieved 11 July 2016.
  4. ^ a b c Masiero, Joseph R.; Grav, T.; Mainzer, A. K.; Nugent, C. R.; Bauer, J. M.; Stevenson, R.; et al. (August 2014). "Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos". The Astrophysical Journal. 791 (2): 11. arXiv:1406.6645. Bibcode:2014ApJ...791..121M. doi:10.1088/0004-637X/791/2/121. Retrieved 5 December 2016.
  5. ^ 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 11 July 2016.
  6. ^ 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. arXiv:1109.6407. Bibcode:2011ApJ...741...90M. doi:10.1088/0004-637X/741/2/90.
  7. ^ a b Pray, Donald P. (September 2005). "Lightcurve analysis of asteroids 106, 752, 847, 1057, 1630, 1670, 1927 1936, 2426, 2612, 2647, 4087, 5635, 5692, and 6235". The Minor Planet Bulletin. 32 (3): 48–51. Bibcode:2005MPBu...32...48P. ISSN 1052-8091. Retrieved 11 July 2016.
  8. ^ a b c Behrend, Raoul. "Asteroids and comets rotation curves – (5692) Shirao". Geneva Observatory. Retrieved 11 July 2016.
  9. ^ a b 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 11 July 2016.
  10. ^ a b "5692 Shirao (1992 FR)". Minor Planet Center. Retrieved 11 July 2016.
  11. ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 11 July 2016.

External links edit