88 Thisbe

From Wikipedia, the free encyclopedia
Jump to: navigation, search
88 Thisbe
88Thisbe (Lightcurve Inversion).png
A three-dimensional model of 88 Thisbe based on its light curve.
Discovery
Discovered by Christian Heinrich Friedrich Peters
Discovery date June 15, 1866
Designations
Pronunciation /ˈθɪzb/ THIZ-bee
Named after Thisbē
Minor planet category Main belt
Adjective Thisbean
Orbital characteristics[1]
Epoch December 31, 2006 (JD 2454100.5)
Aphelion 482.242 Gm (3.224 AU)
Perihelion 345.809 Gm (2.312 AU)
Semi-major axis 414.025 Gm (2.768 AU)
Eccentricity 0.165
Orbital period 1681.709 d (4.60 a)
Average orbital speed 17.78 km/s
Mean anomaly 165.454°
Inclination 5.219°
Longitude of ascending node 276.765°
Argument of perihelion 36.591°
Physical characteristics
Dimensions (255×232×193)±12 km[2]
225 km (mean)
232 km (Dunham)[1]
Mass 1.83×1019 kg[2]
1.5×1019 kg[3][4]
Mean density 2.70±0.50 g/cm³[2]
Equatorial surface gravity 0.0561 m/s²
Escape velocity 0.1061 km/s
Rotation period 6.04[5] h
Albedo 0.067[1][6]
Temperature ~167 K
Spectral type B[1]
Absolute magnitude (H) 7.04[1]

88 Thisbe (/ˈθɪzb/ THIZ-bee) is one of the largest main-belt asteroids. It was discovered by C. H. F. Peters on June 15, 1866, and named after Thisbe, heroine of a Roman fable. An occultation of a star by Thisbe was observed on October 7, 1981. Results from the occultation indicate a larger than expected diameter of 232 km.[7][8]

During 2000, 88 Thisbe was observed by radar from the Arecibo Observatory. The return signal matched an effective diameter of 207 ± 22 km. This is consistent with the asteroid dimensions computed through other means.[9]

Photometric observations of this asteroid during 1977 gave a light curve with a period of 6.0422 ± 0.006 hours and a brightness variation of 0.19 in magnitude.[5]

Perturbation[edit]

Thisbe has been perturbed by asteroid 7 Iris and in 2001 Michalak estimated it to have a mass of 1.5×1019 kg.[3][4] But Iris is strongly perturbed by many minor planets such as 10 Hygiea and 15 Eunomia.[3]

In 2008, Baer estimated Thisbe to have a mass of 1.05×1019 kg.[2] In 2011 Baer revised this to 1.83×1019 kg with an uncertainty of 1.09×1018 kg.[2]

References[edit]

  1. ^ a b c d e Yeomans, Donald K., "88 Thisbe", JPL Small-Body Database Browser (NASA Jet Propulsion Laboratory), retrieved 2013-03-25. 
  2. ^ a b c d e Jim Baer (2011). "Recent Asteroid Mass Determinations". Personal Website. Retrieved 2012-04-12. 
  3. ^ a b c Michalak, G. (2001). "Determination of asteroid masses". Astronomy & Astrophysics 374 (2): 703–711. Bibcode:2001A&A...374..703M. doi:10.1051/0004-6361:20010731. Retrieved 2008-11-06. 
  4. ^ a b (Low mass estimate of Thisbe 0.074 / Mass of Ceres 4.75) * Mass of Ceres 9.43E+20 = 1.469E+19
  5. ^ a b Schober, H. J. et al. (April 1979), "Photoelectric photometry and rotation periods of three large and dark asteroids - 49 Pales, 88 Thisbe and 92 Undina", Astronomy and Astrophysics, Supplement Series 36: 1–8, Bibcode:1979A&AS...36....1S. 
  6. ^ Asteroid Data Sets
  7. ^ Taylor, G. E., "Progress in accurate determinations of diameters of minor planets", Asteroids, comets, meteors; Proceedings of the Meeting, Uppsala, Sweden, June 20–22, 1983: 107–109, Bibcode:1983acm..proc..107T. 
  8. ^ Observed minor planet occultation events, version of 2005 July 26
  9. ^ Magri, Christopher et al. (January 2007), "A radar survey of main-belt asteroids: Arecibo observations of 55 objects during 1999–2003", Icarus 186 (1): 126–151, Bibcode:2007Icar..186..126M, doi:10.1016/j.icarus.2006.08.018