54 Alexandra
Template:Short description Template:Use dmy dates Template:Infobox planet
54 Alexandra is a carbonaceous asteroid from the intermediate asteroid belt, approximately 155 kilometers in diameter. It was discovered by German-French astronomer Hermann Goldschmidt on 10 September 1858, and named after the German explorer Alexander von Humboldt; it was the first asteroid to be named after a male.<ref name="Schmadel2003"/>
Description
On May 17, 2005, this asteroid occulted a faint star (magnitude 8.5) and the event was observed and timed in a number of locations within the U.S. and Mexico. As a result, a silhouette profile was produced, yielding a roughly oval cross-section with dimensions of 160 × 135 km (± 1 km).<ref>D.W. Dunham, "Upcoming Asteroid Occultations", Sky & Telescope, June, 2006, p. 63.</ref> The mass of the asteroid can be estimated based upon the mutually perturbing effects of other bodies, yielding an estimate of Template:Val.<ref name="Carry2012"/>
Photometric observations of this asteroid during 1990–92 gave a light curve with a period of 18.14 ± 0.04 hours and a brightness variation of 0.10 in magnitude.<ref name="Belskaya1993"/> Alexandra has been studied by radar.<ref name="detected"/> It was the namesake and largest member of the former Alexandra asteroid family; a dynamic group of C-type asteroids that share similar orbital elements. Other members included 70 Panopaea and 145 Adeona.<ref name="Williams1988"/> 145 Adeona was subsequently assigned to the Adeona family, with Alexandra and Panopaea being dropped.<ref name="Zappala1990"/>
In popular culture
In the Swedish film Aniara, it is mentioned that 54 Alexandra is the closest celestial body which the off-course and out-of-control spacecraft will approach before it leaves the Solar System.
References
External links
- Lightcurve plot of 54 Alexandra, Palmer Divide Observatory, B. D. Warner (2008)
- Asteroid Lightcurve Database (LCDB), query form (info Template:Webarchive)
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
- Template:AstDys
- Template:JPL small body
Template:Minor planets navigator Template:Small Solar System bodies Template:Authority control