2031 BAM

2031 BAM, provisional designation 1969 TG₂, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 8 kilometers in diameter. It was discovered on 8 October 1969, by Soviet astronomer Lyudmila Chernykh at the Crimean Astrophysical Observatory in Nauchnyj, on the Crimean peninsula.^[8] The asteroid was named for those who built the Baikal–Amur Mainline (BAM; БАМ), a Siberian railway line.^[2]

2031 BAM

Orbital diagram of BAM
Discovery[1]
Discovered by	L. Chernykh
Discovery site	Crimean Astrophysical Obs.
Discovery date	8 October 1969
Designations
MPC designation	(2031) BAM
Named after	Baikal–Amur Mainline[2] (Siberian railway line)
Alternative designations	1969 TG2 · 1939 VB 1959 TW · 1972 NQ
Minor planet category	main-belt · (inner) Flora[3][4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	77.39 yr (28,268 days)
Aphelion	2.6203 AU
Perihelion	1.8477 AU
Semi-major axis	2.2340 AU
Eccentricity	0.1729
Orbital period (sidereal)	3.34 yr (1,220 days)
Mean anomaly	124.02°
Mean motion	0° 17m 42.72s / day
Inclination	4.7524°
Longitude of ascending node	169.28°
Argument of perihelion	213.58°
Physical characteristics
Dimensions	7.14 km (calculated)[3] 8.14±0.36 km[5]
Synodic rotation period	10.774±0.004 h[6]
Geometric albedo	0.170±0.017[5] 0.24 (assumed)[3]
Spectral type	S[3][7]
Absolute magnitude (H)	12.9[1][3] · 13.00[5] · 13.05±0.81[7]

Orbit and classification

BAM is a member of the Flora family (402),^[3][4] a giant asteroid family and the largest family of stony asteroids in the main belt.^[9]: 23 It orbits the Sun in the inner asteroid belt at a distance of 1.8–2.6 AU once every 3 years and 4 months (1,220 days; semi-major axis of 2.23 AU). Its orbit has an eccentricity of 0.17 and an inclination of 5° with respect to the ecliptic.^[1]

The body's observation arc begins with its identification as 1939 VB at Uccle Observatory in November 1939, almost 30 years prior to its official discovery observation at Nauchnyj.^[8]

Physical characteristics

BAM has been characterized as a stony S-type asteroid by Pan-STARRS photometric survey.^[7]

Rotation period

In October 2016, a rotational lightcurve of BAM was obtained from photometric observations by amateur astronomer Matthieu Conjat. Lightcurve analysis gave a well-defined rotation period of 10.774 hours with a brightness amplitude of 0.15 magnitude (U=3).^[6]

Diameter and albedo

According to the survey carried out by the Japanese Akari satellite, BAM measures 8.14 kilometers in diameter and its surface has an albedo of 0.170.^[5] The Collaborative Asteroid Lightcurve Link assumes a standard albedo of 0.24 – derived from 8 Flora, the parent body of the Flora family – and calculates a diameter of 7.14 kilometers based on an absolute magnitude of 12.9.^[3]

Naming

This minor planet was named after those who constructed the Baikal–Amur Mainline (BAM; БАМ) through eastern Russia from 1974 to 1986. The rail line opened in 1989, and runs between Ust-Kut (near Lake Baikal and Komsomolsk-on-Amur.^[2][10] The official naming citation was published by the Minor Planet Center on 1 September 1978 (M.P.C. 4482).^[11]