7866 Sicoli

7866 Sicoli, provisional designation 1982 TK, is a stony Nysa asteroid from the inner regions of the asteroid belt, approximately 6 kilometers in diameter. It was discovered on 13 October 1982, by American astronomer Edward Bowell at Lowell's Anderson Mesa Station near Flagstaff, Arizona.^[7] The asteroid was named after Italian astronomer Piero Sicoli.^[2]

7866 Sicoli

Discovery[1]
Discovered by	E. Bowell
Discovery site	Anderson Mesa Stn.
Discovery date	13 October 1982
Designations
MPC designation	(7866) Sicoli
Named after	Piero Sicoli (discoverer of minor planets)[2]
Alternative designations	1982 TK · 1954 CT 1959 OD
Minor planet category	main-belt · Nysa[3]
Orbital characteristics[1]
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	63.01 yr (23,016 days)
Aphelion	2.9392 AU
Perihelion	1.9165 AU
Semi-major axis	2.4279 AU
Eccentricity	0.2106
Orbital period (sidereal)	3.78 yr (1,382 days)
Mean anomaly	112.12°
Mean motion	0° 15m 37.8s / day
Inclination	3.4801°
Longitude of ascending node	77.978°
Argument of perihelion	253.20°
Physical characteristics
Dimensions	5.604±0.199 km[4][5] 6.34 km (calculated)[3]
Geometric albedo	0.21 (assumed)[3] 0.2455±0.0504[5] 0.246±0.050[4]
Spectral type	S[3]
Absolute magnitude (H)	13.28±0.28[6] · 13.3[1][3] · 13.4[5]

Orbit and classification

Sicoli is a member of the stony subgroup of the Nysa family, one of the smaller families in the main-belt, named after its namesake, 44 Nysa. The body orbits the Sun in the inner main-belt at a distance of 1.9–2.9 AU once every 3 years and 9 months (1,382 days). Its orbit has an eccentricity of 0.21 and an inclination of 3° with respect to the ecliptic.^[1] The first precovery was taken at Palomar Mountain in 1954, extending the asteroid's observation arc by 28 years prior to its discovery.^[7]

Physical characteristics

Diameter and albedo

According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Sicoli measures 6.3 kilometers in diameter and its surface has an albedo of 0.246,^[4][5] while the Collaborative Asteroid Lightcurve Link assumes a standard albedo for stony asteroids of 0.21 and calculates a diameter of 5.6 kilometers, based on an absolute magnitude of 13.3.^[3]

Lightcurves

As of 2016, no rotational lightcurve has been obtained for this asteroid and its rotation period and shape remain unknown.^[1][3]

Naming

This minor planet was named in honor of Italian astronomer Piero Sicoli (born 1954), a discoverer of minor planets and Observation Coordinator at the Sormano Astronomical Observatory in northern Italy.^[2] The official naming citation was published by the Minor Planet Center on 28 July 1999 (M.P.C. 35488).^[8]