Astronomy:1881 Shao

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1881 Shao
Discovery[1]
Discovered byK. Reinmuth
Discovery siteHeidelberg Obs.
Discovery date3 August 1940
Designations
(1881) Shao
Named afterCheng-yuan Shao[1]
(Chinese astronomer)
1940 PC · 1968 OO
Minor planet categorymain-belt[1][2] · (outer)
background[3]
Orbital characteristics[2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc77.71 yr (28,385 d)
|{{{apsis}}}|helion}}3.5061 AU
|{{{apsis}}}|helion}}2.8339 AU
3.1700 AU
Eccentricity0.1060
Orbital period5.64 yr (2,062 d)
Mean anomaly314.29°
Mean motion0° 10m 28.56s / day
Inclination9.8706°
Longitude of ascending node218.07°
66.640°
Physical characteristics
Mean diameter24.083±0.134 km[4]
25.437±0.176 km[5]
25.46±0.86 km[6]
29.21 km (calculated)[7]
Rotation period5.61±0.07 h[8]
7.452±0.002 h[9]
Geometric albedo0.057 (assumed)[7]
0.0994±0.0087[5]
0.111±0.010[4]
0.115±0.009[6]
C (assumed)[7]
Absolute magnitude (H)11.10[5][6]
11.19±0.04 (R)[8]
11.4[2][7]
11.65±0.25[10]


1881 Shao, provisional designation 1940 PC or 1968 OO, is a background asteroid from the outer regions of the asteroid belt, approximately 25 kilometers (16 miles) in diameter. It was discovered on 3 August 1940, by German astronomer Karl Reinmuth at the Heidelberg Observatory in southwest Germany.[1] The presumed C-type asteroid has a rotation period of 7.45 hours.[7] It was named for Chinese astronomer Cheng-yuan Shao.[1]

Orbit and classification

Shao is a non-family asteroid from the main belt's background population.[3] It orbits the Sun in the outer main-belt at a distance of 2.8–3.5 AU once every 5 years and 8 months (2,062 days; semi-major axis of 3.17 AU). Its orbit has an eccentricity of 0.11 and an inclination of 10° with respect to the ecliptic.[2] The body's observation arc begins with its official discovery observation at Heidelberg in 1940.[1]

Physical characteristics

Shao is an assumed carbonaceous C-type asteroid.[7]

Rotation period

In July 2013, a rotational lightcurve of Shao was obtained from photometric observations by Italian amateur astronomer Silvano Casulli. Lightcurve analysis gave a rotation period of 7.452 hours with a brightness variation of 0.15 magnitude ({{{1}}}).[9] A second lightcurve by astronomers at the Palomar Transient Factory from December 2014, gave a shorter period of 5.61 hours and an amplitude of 0.11 ({{{1}}}), indicative for a rather spherical shape.[7][8]

Diameter and albedo

According to the surveys carried out by the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Shao measures between 24.083 and 25.46 kilometers in diameter and its surface has an albedo between 0.0994 and 0.115.[4][5][6] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for a carbonaceous asteroid of 0.057, and calculates a diameter of 29.21 kilometers based on an absolute magnitude of 11.4.[7]

Naming

This minor planet was named after Chinese astronomer Cheng-yuan Shao (born 1927), an assistant to Richard McCrosky (see previously numbered 1880 McCrosky) in Harvard's minor-planet program at the Harvard–Smithsonian Center for Astrophysics and Oak Ridge Observatory in Massachusetts, United States. Shao was also involved in the recovery of near-Earth asteroid 1862 Apollo.[1] The official naming citation was published by the Minor Planet Center on 20 February 1976 (M.P.C. 3936).[11]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 "1881 Shao (1940 PC)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=1881. 
  2. 2.0 2.1 2.2 2.3 "JPL Small-Body Database Browser: 1881 Shao (1940 PC)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001881. 
  3. 3.0 3.1 "Asteroid 1881 Shao". Small Bodies Data Ferret. https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=1881+Shao. 
  4. 4.0 4.1 4.2 Masiero, Joseph R.; Mainzer, A. K.; Grav, T.; Bauer, J. M.; Cutri, R. M.; Dailey, J. et al. (November 2011). "Main Belt Asteroids with WISE/NEOWISE. I. Preliminary Albedos and Diameters". The Astrophysical Journal 741 (2): 20. doi:10.1088/0004-637X/741/2/68. Bibcode2011ApJ...741...68M. 
  5. 5.0 5.1 5.2 5.3 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. doi:10.1088/0004-637X/741/2/90. Bibcode2011ApJ...741...90M.  (catalog)
  6. 6.0 6.1 6.2 6.3 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. doi:10.1093/pasj/63.5.1117. Bibcode2011PASJ...63.1117U.  (online, AcuA catalog p. 153)
  7. 7.0 7.1 7.2 7.3 7.4 7.5 7.6 7.7 "LCDB Data for (1881) Shao". Asteroid Lightcurve Database (LCDB). http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=1881%7CShao. 
  8. 8.0 8.1 8.2 Chang, Chan-Kao; Lin, Hsing-Wen (December 2016). "Large Super-fast Rotator Hunting Using the Intermediate Palomar Transient Factory". The Astrophysical Journal Supplement Series 227 (2): 13. doi:10.3847/0067-0049/227/2/20. Bibcode2016ApJS..227...20C. 
  9. 9.0 9.1 Behrend, Raoul. "Asteroids and comets rotation curves – (1881) Shao". Geneva Observatory. http://obswww.unige.ch/~behrend/page4cou.html#001881. 
  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. doi:10.1016/j.icarus.2015.08.007. Bibcode2015Icar..261...34V. 
  11. Schmadel, Lutz D. (2009). "Appendix – Publication Dates of the MPCs". Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008). Springer Berlin Heidelberg. p. 221. doi:10.1007/978-3-642-01965-4. ISBN 978-3-642-01964-7. https://cds.cern.ch/record/1339661. 

External links