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.[11] The asteroid was named after composer Jean Sibelius.[2]
Orbit and classification
Sibelius is a member of the Flora family, one of the largest populations of stony asteroids in the entire main-belt. It orbits the Sun in the inner main-belt 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.[1] The body's observation arc begins with an observation taken at Turku two weeks prior to its official discovery observation.[11]
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.[4][5][6][8][9] 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.[3][7]