3309 Brorfelde
3309 Brorfelde, provisional designation, is a nearly spheroidal, binary Hungaria asteroid from the inner regions of the asteroid belt, approximately 4 kilometers in diameter. It was discovered on 28 January 1982, by Danish astronomers Kaare Jensen and Karl Augustesen at the Brorfelde Observatory near Holbæk, Denmark. It was named for the discovering observatory and the village where it is located.
Orbit and classification
Brorfelde is a bright stony asteroid and member of the Hungaria family, which form the innermost dense concentration of asteroids in the Solar System. It orbits the Sun at a distance of 1.7–1.9 AU once every 2 years and 5 months. Its orbit has an eccentricity of 0.05 and an inclination of 21° with respect to the ecliptic. The body's observation arc begins with its official discovery observation, as no precoveries were taken, and no prior identifications were made.Physical characteristics
On the SMASS taxonomic scheme, Brorfelde is a common stony S-type asteroid.Photometry
Between 2005 and 2010, astronomers Brian Warner and Petr Pravec obtained a large number of rotational lightcurves of Brorfelde. Best rated lightcurve analysis gave a rotation period between 2.5041 and 2.5046 hours with a brightness amplitude between 0.09 and 0.13 in magnitude, indicating that the body has a nearly spheroidal shape.These results superseded photometric observations taken by Wiesław Z. Wiśniewski in the 1990s, and by Federico Manzini and René Roy in 2005 and 2009, respectively, as well as observations taken at the Palomar [Transient Factory] in 2010, which gave an incorrect period solution of more than 9 hours.