23 Thalia

23 Thalia (/θəˈlaɪ.ə/^[a]) is a large main-belt asteroid. It was discovered by J. R. Hind on 15 December 1852, at the private observatory of W. Bishop, located in Hyde Park, London, England.^[5] Bishop named it after Thalia, the Muse of comedy and pastoral poetry in Greek mythology.^[6]

DiscoveredbyJ. R. Hind

Discoverydate15 December 1852

MPCdesignation

(23) Thalia

Pronunciation/θəˈlaɪ.ə/^[1][a]

Quick facts Discovery, Discovered by ...

23 Thalia

A three-dimensional model of 23 Thalia based on its light curve with an image of Thalia on the bottom.
Discovery
Discovered by	J. R. Hind
Discovery date	15 December 1852
Designations
MPC designation	(23) Thalia
Pronunciation	/θəˈlaɪ.ə/[1][a]
Named after	Thalia
Alternative designations	1938 CL; 1974 QT2
Minor planet category	Main belt
Orbital characteristics
Epoch 14 June 2006 (JD 2453900.5)
Aphelion	484.663 million km (3.240 AU)
Perihelion	301.483 million km (2.015 AU)
Semi-major axis	393.073 million km (2.628 AU)
Eccentricity	0.233
Orbital period (sidereal)	1555.679 d (4.26 a)
Mean anomaly	328.687°
Inclination	10.145°
Longitude of ascending node	67.228°
Argument of perihelion	59.311°
Physical characteristics
Dimensions	107.53 ± 2.2 km (IRAS)[2] 106.81 ± 3.23 km[3]
Mass	(1.96 ± 0.09) × 1018 kg[3]
Mean density	3.07 ± 0.31 g/cm3[3]
Synodic rotation period	12.312 h[2]
Geometric albedo	0.2536 (geometric)[4]
Spectral type	S[2]
Apparent magnitude	9.11 to 13.19
Absolute magnitude (H)	7.17[2]

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It is categorized as an S-type asteroid consisting of mainly of iron- and magnesium-silicates. This the second most common type of asteroid in the main belt. Based on analysis of the light curve, the object has a sidereal rotation period of 0.513202 ± 0.000002 days. An ellipsoidal model of the light curve gives an a/b ratio of 1.28 ± 0.05.^[7]

With a semimajor axis of 2.628, the asteroid is orbiting between the 3:1 and 5:2 Kirkwood gaps in the main belt.^[8] Its orbital eccentricity is larger than the median value of 0.07 for the main belt, and the inclination is larger than the median of below 4°. But most of the main-belt asteroids have an eccentricity of no more than 0.4 and an inclination of up to 30°, so the orbit of 23 Thalia is not unusual for a main-belt asteroid.^[9]

Thalia has been studied by radar.^[10]