2121 Sevastopol

2121 Sevastopol, provisional designation 1971 ME, is a stony Florian asteroid and synchronous binary system from the inner regions of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 27 June 1971, by Russian astronomer Tamara Smirnova at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula.^[7] Its minor-planet moon was discovered in 2010.

2121 Sevastopol

Discovery[1]
Discovered by	T. Smirnova
Discovery site	Crimean Astrophysical Obs.
Discovery date	27 June 1971
Designations
MPC designation	(2121) Sevastopol
Pronunciation	/səˈvæstəpoʊl/[2]
Named after	Sevastopol city[3]
Alternative designations	1971 ME · 1932 HM 1936 WD · 1938 DY 1939 TO · 1952 SZ 1968 QJ1 · 1977 ED2 1978 WG
Minor planet category	main-belt · Flora[4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	79.82 yr (29,154 days)
Aphelion	2.5731 AU
Perihelion	1.7945 AU
Semi-major axis	2.1838 AU
Eccentricity	0.1783
Orbital period (sidereal)	3.23 yr (1,179 days)
Mean anomaly	94.889°
Mean motion	0° 18m 19.44s / day
Inclination	4.3780°
Longitude of ascending node	145.72°
Argument of perihelion	160.38°
Known satellites	1[4][5]
Physical characteristics
Dimensions	8.736±0.037 km[6] 12.48 km (calculated)[4]
Synodic rotation period	2.90640 h[4]
Geometric albedo	0.24 (assumed)[4] 0.308±0.023[6]
Spectral type	S[4]
Absolute magnitude (H)	12.2

Satellite

Discovery
Discovered by	D. Higgins, P. Pravec, P. Kusnirak, J. Pollock, J. Oey, M. Husarik, G. Cervak, D. E. Reichart, K. M. Ivarsen, J. B. Haislip, and A. LaCluyze
Discovery date	2010/07/23
Detection method	Light curve
Orbital characteristics
Semi-major axis	26 km
Orbital period (sidereal)	1.546 d 13 hours, 6 minutes
Angular distance	46 mas (maximum)
Satellite of	2121 Sevastopol
Physical characteristics
Dimensions	3.54 ± 0.17 km
Volume	20.0-26.7 km3 (assumed)
Apparent magnitude	1.9 ± 0.1 fainter than primary
Absolute magnitude (H)	~16.1

Orbit and characterization

Sevastopol is a member of the Flora family, one of the largest groups of stony asteroids in the main-belt. It orbits the Sun in the inner main-belt at a distance of 1.8–2.6 AU once every 3 years and 3 months (1,179 days). Its orbit has an eccentricity of 0.18 and an inclination of 4° with respect to the ecliptic.^[1]

Satellite

In 2010, a minor-planet moon was discovered around Sevastopol, orbiting at a distance of 26 kilometers with a diameter of 3.54 ± 0.17 km.^[5]

Naming

The asteroid was named after the Crimean city on the 200th anniversary of its foundation.^[3] The approved naming citation was published by the Minor Planet Center on 28 January 1983 (M.P.C. 7616).^[8]