Discovered by Y. Väisälä Minor planet category main-belt · (outer) Orbits Sun Asteroid group Asteroid belt | Discovery date 9 September 1939 Pronunciation pæi(j)ænːe Discovered 9 September 1939 Discoverer Yrjö Väisälä Discovery site Iso-Heikkilä Observatory | |
Alternative names 1939 RC · 1933 QE11944 OA · 1956 XB1985 XE2 · A916 OB People also search for 1519 Kajaani, 1530 Rantaseppä | ||
1535 Päijänne (pæi(j)ænːe), provisional designation 1939 RC, is an asteroid from the outer region of the asteroid belt, approximately 25 kilometers in diameter. It was discovered on 9 September 1939, by Finnish astronomer Yrjö Väisälä at the Turku Observatory in Southwest Finland.
Päijänne orbits the Sun at a distance of 2.6–3.8 AU once every 5 years and 8 months (2,056 days). Its orbit has an eccentricity of 0.19 and an inclination of 6° with respect to the ecliptic. It was first identified as A916 OB at Simeiz Observatory in 1916. The body's observation arc begins 6 years prior to its official discovery with its identification as 1933 QE1 at Heidelberg Observatory.
In September 2006, a rotational light-curve of Päijänne was obtained from photometric observations taken by French amateur astronomer Laurent Bernasconi. The light-curve analysis gave a well-defined rotation period of 8.8448 hours with a change in brightness of 0.50 magnitude (U=3).
This asteroid is classified as both S-type and transitional CX-type asteroid. According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Päijänne measures between 23.836 and 26.72 kilometers in diameter, and its surface has an albedo between 0.1299 and 0.164. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0638 and a diameter of 26.36 kilometers using an absolute magnitude of 11.5.
Päijänne was named for Finland's second largest lake, Päijänne, located in south-central Finland, and more than a thousand square kilometers in size. Naming citation was published before November 1977 (M.P.C. 3929).