9165 Raup

9165 Raup, provisional designation 1987 SJ₃, is a stony Hungaria asteroid and exceptionally slow rotator from the inner regions of the asteroid belt, approximately 4.7 kilometers in diameter.

9165 Raup

Discovery[1]
Discovered by	C. Shoemaker E. Shoemaker
Discovery site	Palomar Obs.
Discovery date	27 September 1987
Designations
MPC designation	(9165) Raup
Named after	David M. Raup (paleontologist)[2]
Alternative designations	1987 SJ3 · 1955 BF1 1973 UH
Minor planet category	main-belt · (inner)[1] Hungaria[3][4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	29.60 yr (10,810 days)
Aphelion	2.1792 AU
Perihelion	1.7932 AU
Semi-major axis	1.9862 AU
Eccentricity	0.0972
Orbital period (sidereal)	2.80 yr (1,022 days)
Mean anomaly	264.67°
Mean motion	0° 21m 7.56s / day
Inclination	24.598°
Longitude of ascending node	15.003°
Argument of perihelion	332.15°
Physical characteristics
Dimensions	4.62 km (calculated)[4] 4.839±0.167 km[5]
Synodic rotation period	560±25 h (dated)[6] 1320±10 h[7]
Geometric albedo	0.30 (assumed)[4] 0.329±0.058[5]
Spectral type	S[4]
Absolute magnitude (H)	13.40[5] · 13.6[1][4]

It was discovered on 27 September 1987, by American astronomer couple Carolyn and Eugene Shoemaker at the U.S. Palomar Observatory in California.^[3] The asteroid was later named after American paleontologist David M. Raup.^[2]

Classification and orbit

Raup is a bright S-type asteroid is a member of the Hungaria family, which form the innermost dense concentration of asteroids in the Solar System. It orbits the Sun in the innermost main-belt at a distance of 1.8–2.2 AU once every 2 years and 10 months (1,022 days). Its orbit has an eccentricity of 0.10 and an inclination of 25° with respect to the ecliptic.^[1]

It was first identified as 1955 BF₁ at the discovering observatory in 1955, extending the body's observation arc by 32 years prior to its official discovery observation.^[3]

Physical characteristics

Slow rotator

In September 2015, a rotational lightcurve of Raup was obtained from photometric observations by American astronomer Brian Warner at his Palmer Divide Station in Colorado. It gave a well-defined rotation period of 1320±10 hours with a brightness variation of 1.34 magnitude (U=3-).^[7]

As of 2016, it is the 3rd slowest rotating minor planet in the Light Curve Data Base (LCDB).^[4] Also, the lightcurve's high amplitude indicates that the body has a non-spheroidal shape. Brian Warner's 2015-observation supersedes a previously obtained lightcurve that gave a significantly shorter period of 560±25 hours with an amplitude of 1.05 magnitude (U=2).^[6]

Diameter and albedo

According to the survey carried out by the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Raup measures 4.8 kilometers in diameter and its surface has a high albedo of 0.329,^[5] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for Hungaria asteroids of 0.30, and calculates a diameter of 4.6 kilometers, based on an absolute magnitude of 13.6.^[4]

Naming

This minor planet was named in honor of American David M. Raup (1933–2015), paleontologist and expert on the fossil record at UChicago. Raup's theories contributed to the knowledge of extinction events and suggested, that the extinction of dinosaurs was part of a cycle of mass extinctions.^[2] the official naming citation was published on 23 November 1999 (M.P.C. 36947).^[8]