5222 Ioffe

5222 Ioffe, provisional designation 1980 TL₁₃, is a rare-type carbonaceous Palladian asteroid from the central region of the asteroid belt, approximately 18 kilometers in diameter. It was discovered on 11 October 1980, by Soviet astronomer Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnyj, Crimea.^[3] It is the largest of the Palladian asteroids apart from Pallas itself.

5222 Ioffe

Rotating frame animation in reference to Jupiter. Each frame 81 years.
Discovery[1]
Discovered by	N. S. Chernykh
Discovery site	Crimean Astrophysical Obs.
Discovery date	11 October 1980
Designations
MPC designation	(5222) Ioffe
Named after	Abram Ioffe (Soviet physicist)[2]
Alternative designations	1980 TL13 · 1978 LP 1989 TG1
Minor planet category	main-belt[1][3] · (middle) Pallas[4]
Orbital characteristics[1]
Epoch 16 February 2017 (JD 2457800.5)
Uncertainty parameter 0
Observation arc	64.08 yr (23,405 days)
Aphelion	3.1728 AU
Perihelion	2.3788 AU
Semi-major axis	2.7758 AU
Eccentricity	0.1430
Orbital period (sidereal)	4.62 yr (1,689 days)
Mean anomaly	172.25°
Mean motion	0° 12m 47.16s / day
Inclination	34.539°
Longitude of ascending node	220.66°
Argument of perihelion	331.02°
Physical characteristics
Dimensions	17.989±0.093 km[5] 21.73 km[6]
Synodic rotation period	19.4 h[6]
Geometric albedo	0.1031[6] 0.1463±0.012 0.202±0.041[5]
Spectral type	B (SMASSII)[1]
Absolute magnitude (H)	11.4[1]

Classification and orbit

Rotating frame animation in reference to Pallas, showing how Ioffe is in the group with the obvious 1:1 resonance.

Ioffe is a member of the Pallas family (801), a small, carbonaceous asteroid family in the central main-belt.^[4][7]: 23

It orbits the Sun at a distance of 2.4–3.2 AU once every 4 years and 7 months (1,689 days). Its orbit has an eccentricity of 0.14 and an inclination of 35° with respect to the ecliptic.^[1] A first precovery was taken at Palomar Observatory in 1952, extending the asteroid's observation arc by 28 years prior to its official discovery observation at Nauchnyj.^[3]

Physical characteristics

In the SMASS classification Ioffe is a carbonaceous B-type asteroid, in line with the overall spectral type of the Palladian asteroids.^[1][7]: 23

Photometric observations of this asteroid collected during 2006 show a rotation period of 19.4 ± 0.2 hours with a brightness variation of 0.27 ± 0.03 magnitude.^[8]

Naming

This minor planet was named in memory of Soviet physicist Abram Ioffe (1880–1960), an expert in electromagnetism, radiology, crystals, high-impact physics, thermoelectricity and photoelectricity. Ioffe was a pioneer in the investigation of semiconductors. Proposed by the Institute of Theoretical Astronomy, naming citation was published on 5 March 1996 (M.P.C. 26763).^[2][9]