11885 Summanus

11885 Summanus
Discovery
Discovered by	Spacewatch
Discovery site	Kitt Peak Obs.
Discovery date	25 September 1990
Designations
MPC designation	1990 SS
Pronunciation	/sʌˈmeɪnəs/
Named after	Summānus
Minor planet category	NEO · Apollo
Orbital characteristics
Epoch 4 September 2017 (JD 2458000.5)
Uncertainty parameter 0
Observation arc	20.54 yr (7,504 days)
Aphelion	2.5119 AU
Perihelion	0.8950 AU
Semi-major axis	1.7035 AU
Eccentricity	0.4746
Orbital period (sidereal)	2.22 yr (812 days)
Mean anomaly	346.75°
Mean motion	0° 26^m 35.88^s / day
Inclination	19.419°
Longitude of ascending node	359.89°
Argument of perihelion	116.07°
Earth MOID	0.0689 AU (26.8 LD)
Physical characteristics
Mean diameter	1.298±0.446 km
Synodic rotation period	7.358 h
Geometric albedo	0.033±0.029
Absolute magnitude (H)	18.5

11885 Summanus (prov. designation: 1990 SS) is a dark asteroid and large near-Earth object of the Apollo group. It was discovered by astronomers with the Spacewatch programm at Kitt Peak Observatory on 25 September 1990. The object has a rotation period of 7.3 hours and measures approximately 1.3 kilometers (0.8 miles) in diameter. It was named after Summanus, the Roman deity of nocturnal lightning and thunder.