1220 Crocus

1220 Crocus, provisionally designated 1932 CU, is a stony Eoan asteroid and slow rotator from the outer regions of the asteroid belt, approximately 17 kilometers in diameter. It was discovered on 11 February 1932, by German astronomer Karl Reinmuth at Heidelberg Observatory in southwest Germany.^[7]

1220 Crocus

Shape model of Crocus from its lightcurve
Discovery[1]
Discovered by	K. Reinmuth
Discovery site	Heidelberg Obs.
Discovery date	11 February 1932
Designations
MPC designation	(1220) Crocus
Pronunciation	/ˈkroʊkəs/[2]
Named after	Crocus[3]
Alternative designations	1932 CU · 1955 PC
Minor planet category	main-belt · Eos[4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	85.31 yr (31,161 days)
Aphelion	3.2243 AU
Perihelion	2.7807 AU
Semi-major axis	3.0025 AU
Eccentricity	0.0739
Orbital period (sidereal)	5.20 yr (1,900 days)
Mean anomaly	204.16°
Mean motion	0° 11m 21.84s / day
Inclination	11.365°
Longitude of ascending node	113.34°
Argument of perihelion	333.41°
Physical characteristics
Dimensions	17.866±0.175[5]
Synodic rotation period	491.4±0.1[6]
Geometric albedo	0.114±0.020[5]
Spectral type	S[4]
Absolute magnitude (H)	11.72[1]

Orbit and classification

Crocus is a member of the Eos family, a collisional population of mostly stony composition. It orbits the Sun at a distance of 2.8–3.2 AU once every 5 years and 2 months (1,900 days). Its orbit has an eccentricity of 0.07 and an inclination of 11° with respect to the ecliptic.^[1] A

Physical characteristics

The asteroid has been characterized as a stony S-type asteroid.^[4]

In December 2014, a rotational lightcurve of Crocus was obtained from photometric observations by an international collaboration of several astronomers from Europe and the United States. Lightcurve analysis gave a long rotation period of 491 hours with a brightness variation of 1.00 magnitude (U=3).^[6]

Naming

This minor planet was later named after the genus of flowering plants, Crocus, in the iris family.^[3]