5 Astraea (as-tree'-ə (Pronunciation respelling key ); written Astræa in the early literature) is a large main belt asteroid . Its surface is highly reflective (bright) and its composition is probably a mixture of nickel -iron with magnesium - and iron -silicate s.
Astraea was the fifth asteroid discovered, on December 8 , 1845 by K. L. Hencke . It was his first of two asteroid discoveries. The second was 6 Hebe . An amateur astronomer and post office employee, Hencke was looking for 4 Vesta when he stumbled on Astraea. The King of Prussia awarded him with an annual pension of 300 US$ (1968 dollars) for the discovery.
Photometry indicates prograde rotation, that the north pole points in the direction of right ascension 9h52m, declination 73° with a 5° uncertainty, [3] axial tilt of about 33°.
Astrea is physically unremarkable but notable mainly because for 38 years (since the discovery of Vesta in 1807 ) it had been thought that there were only four asteroids. After the discovery of Astraea, thousands of other asteroids would follow.
There has been only one observed stellar occultation by Astraea (February 2 , 1991 ).
Aspects
! Stationary, retrograde || Opposition || DistanceJune 8 , 2005 || August 2 , 2005 ||align="center"| 2.04497 ||align="center"| 10.9 || September 24 , 2005 || March 6 , 2006
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| September 8 , 2006 || October 24 , 2006 ||align="center"| 1.64421 ||align="center"| 10.3 || December 14 , 2006 || July 2 , 2007
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| February 26 , 2008 || April 5 , 2008 ||align="center"| 1.24209 ||align="center"| 9.4 || May 19 , 2008 || December 11 , 2008
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| May 29 , 2009 || July 23 , 2009 ||align="center"| 2.01466 ||align="center"| 10.9 || September 14 , 2009 || February 25 , 2010
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| August 24 , 2010 || October 11 , 2010 ||align="center"| 1.75512 ||align="center"| 10.5 || December 2 , 2010 || June 9 , 2011
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| February 5 , 2012 || March 13 , 2012 ||align="center"| 1.14353 ||align="center"| 9.1 || April 23 , 2012 || November 28 , 2012
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| May 19 , 2013 || July 13 , 2013 ||align="center"| 1.96537 ||align="center"| 10.9 || September 4 , 2013 || February 16 , 2014
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| August 11 , 2014 || September 29 , 2014 ||align="center"| 1.85053 ||align="center"| 10.7 || November 21 , 2014 || May 20 , 2015
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| January 11 , 2016 || February 17 , 2016 ||align="center"| 1.09393 ||align="center"| 8.7 || March 26 , 2016 || November 13 , 2016
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| May 9 , 2017 || July 2 , 2017 ||align="center"| 1.89739 ||align="center"| 10.8 || August 23 , 2017 || February 6 , 2018
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| July 30 , 2018 || September 18 , 2018 ||align="center"| 1.92870 ||align="center"| 10.8 || November 11 , 2018 || May 3 , 2019
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| December 15 , 2019 || January 22 , 2020 ||align="center"| 1.10914 ||align="center"| 8.9 || March 1 , 2020 || October 28 , 2020
|}
External links
References
G. A. Krasinsky et al
Hidden Mass in the Asteroid Belt , Icarus, Vol. 158, p. 98 (2002).
Main Belt asteroids | Asteroids named from Greek mythology | S-type asteroids
Astraea (Asteroid) | (5) Astraea | Astraea (Asteroid) | (5) Astrea | (5) Astrée | 5 Astraea | 5 Astraea | 5 Astrėja | Astraea | アストラエア (小惑星) | 5 Astraea | 5 Astraea | 5 Astreia | 5 Astraea | 5 Astraea | 義神星
"5 Astraea"