6882 Sormano

6882 Sormano (prov. designation: 1995 CC₁) is an stony Eunomia asteroid from the middle region of the asteroid belt, approximately 7 kilometers (4.3 miles) in diameter. It was discovered on 5 February 1995, by Italian amateur astronomers Piero Sicoli and Valter Giuliani at Sormano Astronomical Observatory in northern Italy.^[1] The asteroid was named for the Italian mountain-village of Sormano and its discovering observatory.^[2]

6882 Sormano

Shape model of Sormano from its lightcurve
Discovery[1]
Discovered by	P. Sicoli V. Giuliani
Discovery site	Sormano Obs.
Discovery date	5 February 1995
Designations
MPC designation	(6882) Sormano
Named after	Sormano Observatory (discovering observatory)[2]
Alternative designations	1995 CC1 · 1986 XM2 1989 OW · 1993 OQ
Minor planet category	main-belt[1][3] · (middle)[4] Eunomia[4] · Maria
Orbital characteristics[3]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	27.85 yr (10,173 days)
Aphelion	2.8043 AU
Perihelion	2.2997 AU
Semi-major axis	2.5520 AU
Eccentricity	0.0989
Orbital period (sidereal)	4.08 yr (1,489 days)
Mean anomaly	327.31°
Mean motion	0° 14m 30.48s / day
Inclination	14.390°
Longitude of ascending node	284.19°
Argument of perihelion	16.030°
Physical characteristics
Mean diameter	6.69 km (calculated)[4] 7.665±0.101 km[5] 8.096±0.040 km[6]
Synodic rotation period	3.6901±0.0006 h[7] 3.998344±0.000001 h[8]
Geometric albedo	0.21 (assumed)[4] 0.269±0.034[6] 0.3003±0.0545[5]
Spectral type	S (family-based)[4]
Absolute magnitude (H)	12.5[5] · 12.7[3] · 12.736±0.003 (R)[7] · 13.19[4]

Orbit and classification

Sormano is a member of the Eunomia family, a large group of S-type asteroids and the most prominent family in the intermediate main-belt. It orbits the Sun at a distance of 2.3–2.8 AU once every 4 years and 1 month (1,489 days). Its orbit has an eccentricity of 0.10 and an inclination of 14° with respect to the ecliptic.^[3] The asteroid's observation arc begins 6 years prior to its discovery, as it had previously been observed as 1989 OW at Palomar Observatory in 1989.^[1]

Naming

This minor planet was named in honor of the Italian mountain-village of Sormano and its discovering nearby observatory. It is funded, built and operated by the "Gruppo Astrofili Brianza", a group of Italian amateur astronomers who have discovered numerous minor planets.^[2] The official naming citation was published by the Minor Planet Center on 3 May 1996 (M.P.C. 27130).^[9]

Physical characteristics

Rotation and shape

In September 2010, a rotational lightcurve of Sormano was obtained from photometric observations made at the Palomar Transient Factory in California. It gave a rotation period of 3.6901 hours with a high brightness variation of 0.71 magnitude, indicative of a non-spheroidal shape (U=2).^[7] A similar period of 3.998 hours was derived from remodeled data of the Lowell photometric database (n.a.).^[8]

Diameter and albedo

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Sormano measures 7.6 to 8.0 kilometers in diameter and its surface has an albedo between 0.269 and 0.300.^[5][6] The Collaborative Asteroid Lightcurve Link assumes an albedo 0.21 – derived from 15 Eunomia, the family's largest member and namesake – and calculates a diameter of 6.69 kilometers with an absolute magnitude of 13.19.^[4]