160 Una

160 Una is a fairly large and dark, primitive Main belt asteroid that was discovered by German-American astronomer C. H. F. Peters on February 20, 1876, in Clinton, New York.^[8] It is named after a character in Edmund Spenser's epic poem The Faerie Queene (1590). This minor planet is orbiting the Sun at a distance of 2.73 AU with an eccentricity of 0.07. The orbital plane is inclined at an angle of 3.83° to the plane of the ecliptic.^[2]

160 Una

A three-dimensional model of 160 Una based on its light curve.
Discovery
Discovered by	C. H. F. Peters
Discovery date	20 February 1876
Designations
MPC designation	(160) Una
Pronunciation	/ˈjuːnə/[1]
Minor planet category	Main belt
Orbital characteristics[2]
Epoch 31 July 2016 (JD 2457600.5)
Uncertainty parameter 0
Observation arc	118.30 yr (43209 d)
Aphelion	2.90877 AU (435.146 Gm)
Perihelion	2.54727 AU (381.066 Gm)
Semi-major axis	2.72802 AU (408.106 Gm)
Eccentricity	0.066257
Orbital period (sidereal)	4.51 yr (1645.8 d)
Average orbital speed	18.01 km/s
Mean anomaly	144.472°
Mean motion	0° 13m 7.471s / day
Inclination	3.82512°
Longitude of ascending node	8.60989°
Argument of perihelion	52.8418°
Earth MOID	1.56031 AU (233.419 Gm)
Jupiter MOID	2.30107 AU (344.235 Gm)
TJupiter	3.349
Physical characteristics
Dimensions	81.24±2.1 km
Mass	5.6×1017 kg (assumed)
Mean density	2.0? g/cm3
Equatorial surface gravity	0.0227 m/s2
Equatorial escape velocity	0.0429 km/s
Synodic rotation period	11.033 h (0.4597 d)[2] 0.234 d (5.61 h)[3][4]
Geometric albedo	0.0625±0.003[2] 0.063[5]
Temperature	~170 K
Spectral type	C[6]
Absolute magnitude (H)	9.08,[2] 8.95[7]

In the Tholen classification system it is categorized as a CX-type, while the Bus asteroid taxonomy system lists it as an Xk asteroid.^[9] Photometric observations of this asteroid made at the Torino Observatory in Italy during 1990–1991 were used to determine a synodic rotation period of 5.61 ± 0.01 hours.^[3] It has an estimated diameter of about 81 km.