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Asteroid 511 Davida imaged by the Keck Observatory, December 2002.
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Discovery
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| Discovered by | R. S. Dugan |
| Discovery date | May 30, 1903 |
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Designations
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| Named after | David Peck Todd |
| Alternate name(s) | 1903 LU |
| Minor planet category |
Main belt |
| Epoch August 27, 2011 (JD 2455800.5) | |
| Aphelion | 3.756248648 AU |
| Perihelion | 2.57323875 AU |
| Semi-major axis | 3.164743701 AU |
| Eccentricity | 0.18690453 |
| Orbital period | 5.63009883 a (2056.393597 d) |
| Average orbital speed | 16.59 km/s |
| Mean anomaly | 202.86548° |
| Inclination | 15.942247° |
| Longitude of ascending node | 107.63617° |
| Argument of perihelion | 338.17810° |
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Physical characteristics
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| Dimensions | 289±21 km (357±2 × 294±2 × 231±50)[2] |
| Mass | 3.84±0.20×1019 kg[3] |
| Mean density | 3.45 ± 1.51 g/cm³[3] |
| Rotation period | 0.2137235 d (5.13 h) |
| Albedo | 0.054–0.066 2 |
| Temperature | ~160 K |
| Spectral type | C |
| Apparent magnitude | 9.50[4] to 12.98 |
| Absolute magnitude (H) | 6.22 |
511 Davida ( /dəˈviːdə/ də-vee-də) 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.[3][5][6] It is a C-type asteroid, which means that it is dark in colouring with a carbonate 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.
In 2001, Michalak estimated Davida to have a mass of (6.64±0.56)×1019 kg[7][8] In 2007, Baer and Chesley estimated Davida to have a mass of (5.9±0.6)×1019 kg.[9] As of 2010[update], Baer suggests Davida has a mass of (3.84±0.20)×1019 kg.[3] 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.[3]
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