3202 Graff

3202 Graff, provisional designation A908 AA, is a carbonaceous Hilda asteroid from the outermost region of the asteroid belt, approximately 36 kilometers in diameter. It was discovered on 3 January 1908, by German astronomer Max Wolf at Heidelberg Observatory in southern Germany.^[7] The asteroid was named after astronomer Gareth V. Williams.^[2]

3202 Graff

Discovery[1]
Discovered by	M. F. Wolf
Discovery site	Heidelberg Obs.
Discovery date	3 January 1908
Designations
MPC designation	(3202) Graff
Named after	Gareth V. Williams (astronomer)[2]
Alternative designations	A908 AA · 1981 ES13
Minor planet category	main-belt[1] · Hilda[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	109.02 yr (39,819 days)
Aphelion	4.3883 AU
Perihelion	3.4843 AU
Semi-major axis	3.9363 AU
Eccentricity	0.1148
Orbital period (sidereal)	7.81 yr (2,853 days)
Mean anomaly	295.10°
Mean motion	0° 7m 34.32s / day
Inclination	11.107°
Longitude of ascending node	205.14°
Argument of perihelion	268.81°
Physical characteristics
Dimensions	35.914±0.244[4] 36.78 km (calculated)[3]
Synodic rotation period	17.32±0.02 h[5]
Geometric albedo	0.055±0.013[4] 0.057 (assumed)[3]
Spectral type	D[6] · C[3]
Absolute magnitude (H)	10.9[1][3] · 11.31±0.28[6]

Orbit and classification

Graff belongs to the Hilda family of asteroids, which are in a 3:2 orbital resonance with the giant planet Jupiter. It orbits the Sun in the outer main-belt at a distance of 3.5–4.4 AU once every 7 years and 10 months (2,853 days). Its orbit has an eccentricity of 0.11 and an inclination of 11° with respect to the ecliptic.^[1] The asteroid's observation arc begins 3 weeks after its discovery with its first used observation at Heidelberg.^[7]

Physical characteristics

The dark C-type asteroid is classified as a rare D-type by Pan-STARRS' large-scale survey,^[6]

In July 2015, a rotational lightcurve of Graff was obtained by astronomer Robert Stephens at the Center for Solar System Studies. It gave a well-defined rotation period of 17.32±0.02 hours with a brightness variation of 0.18 in magnitude (U=3-).^[5]

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Graff measures 35.9 kilometers in diameter and its surface has an albedo of 0.055.^[4] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 36.8 kilometers with an absolute magnitude of 10.9.^[3]

Naming

This minor planet was named after English-born astronomer Gareth "Graff" Vaughan Williams (born 1965), who identified various low-numbered asteroids among bodies that had been given provisional designations. His work at the Minor Planet Center (MPC) has received much recognition.^[2]

The official naming citation was published by the Minor Planet Center on 10 April 1990 (M.P.C. 16245),^[8] based on a suggestion by long-time MPC director Brian G. Marsden (1937–2000) and by Conrad M. Bardwell (1926–2010), associate director of the MPC and who made the identification for this body.^[2] The minor planets 1615 Bardwell and 1877 Marsden were named in honor of these two prominent astronomers at the MPC.