astro.wikisort.org - Asteroid

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]

1881 Shao

Discovery[1]
Discovered by	K. Reinmuth
Discovery site	Heidelberg Obs.
Discovery date	3 August 1940
Designations
MPC designation	(1881) Shao
Named after	Cheng-yuan Shao[1] (Chinese astronomer)
Alternative designations	1940 PC · 1968 OO
Minor planet category	main-belt[1][2] · (outer) background[3]
Orbital characteristics[2]
Epoch 23 March 2018 (JD 2458200.5)
Uncertainty parameter 0
Observation arc	77.71 yr (28,385 d)
Aphelion	3.5061 AU
Perihelion	2.8339 AU
Semi-major axis	3.1700 AU
Eccentricity	0.1060
Orbital period (sidereal)	5.64 yr (2,062 d)
Mean anomaly	314.29°
Mean motion	0° 10m 28.56s / day
Inclination	9.8706°
Longitude of ascending node	218.07°
Argument of perihelion	66.640°
Physical characteristics
Mean diameter	24.083±0.134 km[4] 25.437±0.176 km[5] 25.46±0.86 km[6] 29.21 km (calculated)[7]
Synodic rotation period	5.61±0.07 h[8] 7.452±0.002 h[9]
Geometric albedo	0.057 (assumed)[7] 0.0994±0.0087[5] 0.111±0.010[4] 0.115±0.009[6]
Spectral type	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]

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 (U=2).[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 (U=2), 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

External links

• Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
• Dictionary of Minor Planet Names, Google books
• Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
• Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
• 1881 Shao at AstDyS-2, Asteroids—Dynamic Site
  • Ephemeris · Observation prediction · Orbital info · Proper elements · Observational info
• 1881 Shao at the JPL Small-Body Database
  • Close approach · Discovery · Ephemeris · Orbit diagram · Orbital elements · Physical parameters

На других языках

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[de] (1881) Shao

(1881) Shao ist ein Asteroid des Hauptgürtels, der am 3. August 1940 von dem deutschen Astronomen Karl Wilhelm Reinmuth an der Landessternwarte Heidelberg-Königstuhl der Universität Heidelberg entdeckt wurde.

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- [en] 1881 Shao

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