1304 Arosa

1304 Arosa, provisional designation 1928 KC, is a metallic asteroid from the outer region of the asteroid belt, approximately 40 kilometers in diameter. It was discovered on 21 May 1928, by German astronomer Karl Reinmuth at Heidelberg Observatory in southwest Germany.^[15] It was named after the Swiss mountain village of Arosa.^[2]

1304 Arosa

Discovery[1]
Discovered by	K. Reinmuth
Discovery site	Heidelberg Obs.
Discovery date	21 May 1928
Designations
MPC designation	(1304) Arosa
Named after	Arosa (Swiss village)[2]
Alternative designations	1928 KC · 1929 RY 1934 JL · 1934 LE 1974 OW · A908 YC
Minor planet category	main-belt · (outer)[3] background[4]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	108.22 yr (39,526 days)
Aphelion	3.5731 AU
Perihelion	2.8226 AU
Semi-major axis	3.1978 AU
Eccentricity	0.1173
Orbital period (sidereal)	5.72 yr (2,089 days)
Mean anomaly	207.15°
Mean motion	0° 10m 20.64s / day
Inclination	18.991°
Longitude of ascending node	86.580°
Argument of perihelion	148.26°
Physical characteristics
Dimensions	31.47±3.06 km[5] 41.67 km (derived)[3] 42.94±1.9 km[6] 43.613±0.241 km[7] 48.35±0.81 km[8] 57.443±1.462 km[9]
Synodic rotation period	7.74 h[10] 7.7478±0.0001 h[11][12] 7.77±0.04 h[11]
Geometric albedo	0.1961±0.0279[9] 0.2125 (derived)[3] 0.279±0.011[8] 0.337±0.031[7] 0.3480±0.033[6] 0.409±0.084[5]
Spectral type	SMASS = X[1][3] · M[9]
Absolute magnitude (H)	8.6[6][8][9][13] · 9.03±0.27[14] · 9.10[5] · 9.2[1][3]

Orbit and classification

Arosa is a non-family asteroid from the main belt's background population.^[4] It orbits the Sun in the outer asteroid belt at a distance of 2.8–3.6 AU once every 5 years and 9 months (2,089 days; semi-major axis of 3.20 AU). Its orbit has an eccentricity of 0.12 and an inclination of 19° with respect to the ecliptic.^[1] It was first identified as A908 YC at the discovering observatory in 1908, extending the body's observation arc by 20 years prior to its official discovery.^[15]

Physical characteristics

In the SMASS taxonomy, Arosa is classified as a generic X-type asteroid. The Wide-field Infrared Survey Explorer (WISE) groups it into the metallic M-type asteroid subcategory.^[1][9]

Rotation period

Several rotational lightcurves were obtained from photometric observations between 2002 and 2006. Lightcurve analysis gave a well-defined rotation period of 7.74 hours with a brightness amplitude between 0.32 and 0.38 magnitude (U=3/3/3/2).^[10][11][12]

Diameter and albedo

According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's WISE space telescope with its NEOWISE mission, Arosa measures between 31.47 and 57.443 kilometers in diameter, and its surface has an albedo between 0.1961 and 0.409.^{[5][6][7][8][9]} The Collaborative Asteroid Lightcurve Link derives an albedo of 0.2125 and a diameter of 41.67 kilometers, using an absolute magnitude of 9.2.^[3]

Naming

This minor planet was named for the Swiss mountain village of Arosa, a summer and a winter tourist resort in the Swiss Alps. The official naming citation was also mentioned in The Names of the Minor Planets by Paul Herget in 1955 (H 119).^[2]