Discovered by Y. Väisälä MPC designation 1405 Sibelius Discovered 12 September 1936 Discoverer Yrjö Väisälä Discovery site Iso-Heikkilä Observatory | Discovery date 12 September 1936 Orbits Sun Asteroid group Asteroid belt | |
Alternative names 1936 RE · 1951 CO1953 VK3 · 1963 ST Similar 1450 Raimonda, Sun, 218 Bianca, 45 Eugenia, 216 Kleopatra | ||
1405 Sibelius, provisional designation 1936 RE, is a stony Florian asteroid from the inner regions of the asteroid belt, approximately 8 kilometers in diameter. It was discovered on 12 September 1936, by Finnish astronomer Yrjö Väisälä at Turku Observatory in Southwest Finland.
The asteroid is a member of the Flora family, one of the largest populations of stony S-type asteroids in the entire main-belt. It orbits the Sun at a distance of 1.9–2.6 AU once every 3 years and 5 months (1,234 days). Its orbit has an eccentricity of 0.15 and an inclination of 7° with respect to the ecliptic. The body's observation arc begins with an observation taken at Turku two weeks prior to its official discovery observation.
In October 2007, a rotational light-curve of Sibelius was obtained from photometric observations taken by Petr Pravec at Ondřejov Observatory in the Czech Republic. Light-curve analysis gave a rotation period of 6.051 hours with a brightness variation of 0.11 magnitude (U=3-).
According to the surveys carried out by the Infrared Astronomical Satellite IRAS and NASA's Wide-field Infrared Survey Explorer (WISE) with its subsequent NEOWISE mission, Sibelius measures between 6.21 and 12.18 kilometers in diameter and its surface has an albedo between 0.14 and 0.48. The Collaborative Asteroid Lightcurve Link adopts an albedo of 0.3191 and a diameter of 7.20 kilometers from Petr Pravec's revised WISE thermal observations.
This minor planet was named for Jean Sibelius (1865–1957), Finnish violinist and composer of the late Romantic and early-modern periods. Naming citation was published before November 1977 (M.P.C. 3928).