|Discovered by E. W. Elst|
MPC designation 10121 Arzamas
Observation arc 45.16 yr (16,494 days)
Named after Arzamas (Russian city)
Asteroid group Asteroid belt
|Discovery date 27 January 1993|
Minor planet category main-belt · Themis
Discovered 27 January 1993
Discoverer Eric Walter Elst
Asteroid family Themis family
|Alternative names 1993 BS4 · 1994 GA112118 T-1|
Discovery site Centre de recherches en géodynamique et astrométrie
10121 Arzamas, provisional designation 1993 BS4, is a carbonaceous Themistian asteroid from the outer region of the asteroid belt, approximately 10 kilometers in diameter. It was discovered on 27 January 1993, by Belgian astronomer Eric Elst at Caussols , southeastern France.
The dark C-type asteroid is a member of the Themis family, a dynamical family of outer main-belt asteroids with nearly co-planar ecliptical orbits. It orbits the Sun at a distance of 2.7–3.7 AU once every 5 years and 9 months (2,098 days). Its orbit has an eccentricity of 0.15 and an inclination of 1° with respect to the ecliptic. The first precovery was taken at Palomar Observatory in 1971, extending the asteroid's observation arc by 22 years prior to its discovery.
Two rotational light-curves for this asteroid were obtained from photometric observations made at the U.S. Palomar Transient Factory in February 2010. The light-curves rendered a rotation period of 7001121000000000000♠12.1±0.3 and 7001121991000000000♠12.1991±0.0060 hours with a brightness amplitude of 0.7 and 0.6 in magnitude, respectively (U=2/2). According to the NEOWISE mission of NASA's space-based Wide-field Infrared Survey Explorer, the asteroid measures 10.8 kilometer in diameter based on an albedo of 0.08. The Collaborative Asteroid Lightcurve Link also assumes an albedo of 0.08 and calculates a diameter of 10.3 kilometers.
The minor planet is named after the Russian city of Arzamas, a major transit center on the road from Moscow to the eastern parts of the country. It was founded in 1578 by Ivan the Terrible and is located on the Tyosha River, known for making leather and dyeing fabrics ever since. Naming citation was published on 24 November 2007 (M.P.C. 61266).