30 Urania

Not to be confused with the Solar system planet Uranus.

30 Urania is a large main-belt asteroid that was discovered by English astronomer John Russell Hind on July 22, 1854.^[1] It was his last asteroid discovery. This object is named after Urania, the Greek Muse of astronomy. Initial orbital elements for 30 Urania were published by Wilhelm Günther, an assistant at Breslau Observatory.^[7] It is orbiting the Sun with a period of 3.64 years and is spinning on its axis once every 13.7 hours.

30 Urania

Discovery[1]
Discovered by	J. R. Hind
Discovery date	July 22, 1854
Designations
MPC designation	(30) Urania
Pronunciation	/jʊəˈreɪniə/ yoor-AY-nee-ə[2]
Named after	Urania
Alternative designations	1948 JK
Minor planet category	Main belt
Symbol	(astrological)
Orbital characteristics[3]
Epoch 17.0 October 2024 (JD 2460600.5)
Aphelion	398.863 Gm (2.666 AU)
Perihelion	309.039 Gm (2.066 AU)
Semi-major axis	353.951 Gm (2.366 AU)
Eccentricity	0.127
Orbital period (sidereal)	1,329.308 d (3.64 a)
Mean anomaly	211.291°
Inclination	2.093°
Longitude of ascending node	307.403°
Argument of perihelion	87.100°
Earth MOID	1.07287 AU
Jupiter MOID	2.74597 AU
TJupiter	3.536
Physical characteristics
Dimensions	112 km × 84 km × 76 km (± 5 km × 5 km × 4 km)[4]
Mean diameter	88±2 km[4] 92.787±2.040 km (NEOWISE)[3] 94.48±5.37 km[5][a]
Flattening	0.32 ± 0.05[b]
Mass	(1.3±0.9)×1018 kg[4][a] (1.74±0.49)×1018 kg[5][a]
Mean density	3.7±2.7 g/cm3[4] 3.92±1.29 g/cm3[5]
Synodic rotation period	13.686 h (0.5703 d)[6][3]
Axial tilt	72°[4]
Pole ecliptic longitude	106°±2°[4]
Pole ecliptic latitude	19°±2°[4]
Geometric albedo	0.214 (calculated)[4] 0.192 ± 0.027[3]
Spectral type	S[3][4][5]
Apparent magnitude	9.36 (brightest)
Absolute magnitude (H)	7.59[3] 7.57[4]

Based upon its spectrum, this is classified as a stony S-type asteroid.^[8] During 2000, speckle interferometry measurements from the Telescopio Nazionale Galileo in the Canary Islands were used to measure the apparent size and shape of 30 Urania. This gave cross-sectional dimensions equivalent to an ellipse with a length of 111 km and a width of 89 km, for a ratio of 0.80.^[9]

The astrological symbol for Urania is , compass calipers.^[10]

Notes

1. Composite estimate.
2. Flattening derived from the maximum aspect ratio (c/a): ${\displaystyle f=1-{\frac {c}{a}}}$, where (c/a) = 0.68±0.05.^[4]