511 Davida

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**511 Davida**
Discovery
Discovered by:	R. S. Dugan
Discovery date:	May 30, 1903
Alternative names:	1903 LU
Minor planet category:	Main belt
Orbital characteristics
Epoch October 22, 2004 (JD 2453300.5)
Aphelion distance:	561.538 Gm (3.754 AU)
Perihelion distance:	385.946 Gm (2.580 AU)
Semi-major axis:	473.742 G m (3.167 AU)
Eccentricity:	0.185
Orbital period:	2058.370 d (5.64 a)
Avg. orbital speed:	16.59 km/s
Mean anomaly:	124.997°
Inclination:	15.936°
Longitude of ascending node:	107.683°
Argument of perihelion:	338.694°
Physical characteristics
Dimensions:	326.1 km
Mass:	3.6×10¹⁹ kg
Mean density:	2.0 g/cm³
Equatorial surface gravity:	0.0911 m/s²
Escape velocity:	0.1724 km/s
Rotation period:	0.2137 d ¹
Albedo:	0.054–0.066 ²
Temperature:	~160 K
Spectral type:	C
Absolute magnitude:	6.22

511 Davida (da-vee'-da ?) is a large main belt asteroid. It was discovered by R. S. Dugan in 1903. It is thought to be the sixth largest asteroid, measuring 326 km in diameter and comprising an estimated 1.3% of the total mass of the asteroid belt. 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. In 2002, astronomers at the Keck Observatory used the Keck II telescope, which is fitted with adaptive optics, to photograph Davida. The image revealed a semi-oblong object with at least two flat facets. Its rotation period is about 5 hours.

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

Asteroid 511 Davida imaged by the Keck Observatory, December 2002.

[edit] Aspects

Stationary, then retrograde	Opposition	Distance to earth	Brightness	Stationary, then prograde	Conjunction to sun
10th April 2005	7th June 2005	2.73453 AU	11.6 mag	7th August 2005	2nd January 2006
9th June 2006	31st July 2006	2.53332 AU	11.2 mag	26th September 2006	28th February 2007
7th September 2007	19th October 2007	1.87396 AU	10.4 mag	13th December 2007	14th June 2008
31st December 2008	9th February 2009	1.80046 AU	10.1 mag	31st March 2009	30th September 2009
11th March 2010	2nd May 2010	2.54593 AU	11.4 mag	3rd July 2010	2nd December 2010
29th April 2011	27th June 2011	2.72809 AU	11.4 mag	25th August 2011	21st January 2012
8th July 2012	23rd August 2012	2.33268 AU	11.1 mag	19th October 2012	30th March 2013
15th October 2013	29th November 2013	1.65151 AU	9.9 mag	17th January 2014	30th July 2014
2nd February 2015	16th March 2015	2.10313 AU	10.8 mag	13th May 2015	27th October 2015
28th March 2016	23rd May 2016	2.68460 AU	11.6 mag	24th July 2016	19th December 2016
20th May 2017	15th July 2017	2.64543 AU	11.3 mag	11th September 2017	10th February 2018
11th August 2018	21st September 2018	2.08275 AU	10.7 mag	18th November 2018	10th May 2019
28th November 2019	11th January 2020	1.63769 AU	9.5 mag	25th February 2020	6th September 2020