511 Davida

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511 Davida
DavidaNGC5792-mag12.jpg
Asteroid 511 Davida (lower left at apparent magnitude 12.5) near galaxy NGC 5792.
Discovery
Discovered by R. S. Dugan
Discovery date May 30, 1903
Designations
Pronunciation /dəˈvdə/ or /ˈdævɨdə/[1]
Named after
David Peck Todd
1903 LU
Minor planet category Main belt
Orbital characteristics[2]
Epoch August 27, 2011 (JD 2455800.5)
Aphelion 3.756248648 AU
Perihelion 2.57323875 AU
3.164743701 AU
Eccentricity 0.18690453
5.63009883 a (2056.393597 d)
16.59 km/s
202.86548°
Inclination 15.942247°
107.63617°
338.17810°
Physical characteristics
Dimensions 289±21 km (357±2 × 294±2 × 231±50)[3]
Mass 3.84±0.20×1019 kg[4]
Mean density
3.45 ± 1.51 g/cm³[4]
0.2137235 d (5.13 h)
Albedo 0.054–0.066 2
Temperature ~160 K
Spectral type
C
9.50[5] to 12.98
6.22

511 Davida is a large main-belt C-type asteroid. It was discovered by R. S. Dugan in 1903. It is one of the ten most massive asteroids. It is approximately 270–310 km in diameter and comprises an estimated 1.5% of the total mass of the asteroid belt.[4][6][7] It is a C-type asteroid, which means that it is dark in colouring with a carbonaceous chondrite composition.

Davida is one of the few main-belt asteroids whose shape has been determined by ground-based visual observation. From 2002 to 2007, astronomers at the Keck Observatory used the Keck II telescope, which is fitted with adaptive optics, to photograph Davida. The asteroid is not a dwarf planet: there are at least two promontories and at least one flat facet with 15-km deviations from a best-fit ellipsoid. The facet is presumably a 150-km global-scale crater like the ones seen on 253 Mathilde. Conrad et al. (2007) show that craters of this size "can be expected from the impactor size distribution, without likelihood of catastrophic disruption of Davida."

Davida is named after David Peck Todd, an astronomy professor at Amherst College.

Mass[edit]

In 2001, Michalak estimated Davida to have a mass of (6.64±0.56)×1019 kg[8][9] In 2007, Baer and Chesley estimated Davida to have a mass of (5.9±0.6)×1019 kg.[10] As of 2010, Baer suggests Davida has a mass of (3.84±0.20)×1019 kg.[4] This most recent estimate by Baer suggests that Davida is less massive than 704 Interamnia, making Davida the sixth-most-massive asteroid, though the error bars overlap.[4]

Occultations[edit]

Davida occulted the star TYC 0079-00234-1 on August 5, 2013.[11] The event was visible over Argentina and Chile, with Davida at magnitude 11.7 and the star at mag 9.4.[11]

References[edit]

  1. ^ də-VY-də or DAV-i-də
  2. ^ JPL data Retrieved 2011-09-02
  3. ^ Conrad (2007). Measurements of the short axis are less precise than the other two, but also involve a discrepancy between fitting the convolved and deconvolved images (241±40 km), and fitting the edges (191±114 km).
  4. ^ a b c d e Baer, James (2010). "Recent Asteroid Mass Determinations". Personal Website. Retrieved 2011-02-13. 
  5. ^ "Bright Minor Planets 2003". Minor Planet Center. Retrieved 2008-05-21. 
  6. ^ Pitjeva, E. V. (2005). "High-Precision Ephemerides of Planets—EPM and Determination of Some Astronomical Constants" (PDF). Solar System Research 39 (3): 176. Bibcode:2005SoSyR..39..176P. doi:10.1007/s11208-005-0033-2. 
  7. ^ "Baer Mass of 511 Davida" 0.220 / "Mass of Mbelt" 15 = 0.0146
  8. ^ Michalak, G. (2001). "Determination of asteroid masses (6) Hebe, (10) Hygiea, (15) Eunomia, (52) Europa, (88) Thisbe, (444) Gyptis, (511) Davida and (704) Interamnia". Astronomy & Astrophysics 374: 703–711. Bibcode:2001A&A...374..703M. doi:10.1051/0004-6361:20010731. Retrieved 2008-11-04. 
  9. ^ (3.34±0.28)×10−11 solar masses, per Michalak (2001), extended dynamic model.
  10. ^ Baer, James; Steven R. Chesley (2007). "Astrometric masses of 21 asteroids, and an integrated asteroid ephemeris" (PDF). Celestial Mechanics and Dynamical Astronomy (Springer Science+Business Media B.V. 2007) 100 (2008): 27–42. Bibcode:2008CeMDA.100...27B. doi:10.1007/s10569-007-9103-8. Retrieved 2008-11-15. : = (2.98±0.30)×10−11*solar masses
  11. ^ a b Asteroid Occultations

External links[edit]