23 Thalia

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23 Thalia
23Thalia (Lightcurve Inversion).png
A three-dimensional model of 23 Thalia based on its light curve.
Discovery
Discovered by J. R. Hind
Discovery date December 15, 1852
Designations
Pronunciation /θəˈl.ə/ thə-LY
Named after Thalia
Alternative names 1938 CL; 1974 QT2
Minor planet category Main belt
Orbital characteristics
Epoch June 14, 2006 (JD 2453900.5)
Aphelion 484.663 Gm (3.240 AU)
Perihelion 301.483 Gm (2.015 AU)
Semi-major axis 393.073 Gm (2.628 AU)
Eccentricity 0.233
Orbital period 1555.679 d (4.26 a)
Average orbital speed 18.12 km/s
Mean anomaly 328.687°
Inclination 10.145°
Longitude of ascending node 67.228°
Argument of perihelion 59.311°
Physical characteristics
Dimensions 107.5 ± 2.2 km (IRAS)[1]
106.81 ± 3.23[2] km
Mass (1.96 ± 0.09) × 1018[2] kg
Mean density 3.07 ± 0.31[2] g/cm3
Equatorial surface gravity 0.0300? m/s²
Escape velocity 0.0568? km/s
Rotation period 12.312 h[1]
Albedo 0.2536 (geometric)[3]
Temperature ~164 K
Spectral type S[1]
Apparent magnitude 9.11 to 13.19
Absolute magnitude (H) 6.95[1]

23 Thalia[4] is a large main-belt asteroid. It was discovered by J. R. Hind on December 15, 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]

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 /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]

References[edit]

  1. ^ a b c d "JPL Small-Body Database Browser: 23 Thalia". Jet Propulsion Laboratory. 2011-04-30 last obs. Retrieved 2012-01-28. 
  2. ^ a b c Carry, B. (December 2012), "Density of asteroids", Planetary and Space Science 73: 98-118, arXiv:1203.4336, Bibcode:2012P&SS...73...98C, doi:10.1016/j.pss.2012.03.009.  See Table 1.
  3. ^ "Albedos Data Table". Planetary Science Institute. Retrieved 2008-11-03. 
  4. ^ Stressed on the second syllable, /θəˈl.ə/ thə-LY.
  5. ^ Hand-books of natural philosophy and astronomy 3. Philadelphia: Blanchard and Lea. 1858. p. 315. Retrieved 2009-11-10. 
  6. ^ Schmadel, Lutz D. (2003). Dictionary of minor planet names (5th ed.). Springer. p. 17. ISBN 3-540-00238-3. 
  7. ^ Lagerkvist, C.-I.; et al. (October 1995). "Physical studies of asteroids. XXIX. Photometry and analysis of 27 asteroids". Astronomy and Astrophysics Supplement 113: 115–122. Bibcode:1995A&AS..113..115L. 
  8. ^ Yeomans, Donald K. "Asteroid Main-Belt Distribution". NASA/Jet Propulsion Laboratoty. Retrieved 2009-11-10. 
  9. ^ Williams, Gareth (April 3, 2007). "Distribution of the Minor Planets". Minor Planets Center. Archived from the original on 21 March 2007. Retrieved 2007-04-15. 
  10. ^ "Radar-Detected Asteroids and Comets". NASA/JPL Asteroid Radar Research. Retrieved 2011-10-30. 

External links[edit]