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.[10] It was later named for Lake Päijänne.[2]
Orbit
Päijänne orbits the Sun in the outer main-belt at a distance of 2.6–3.8 AU once every 5 years and 8 months (2,057 days). Its orbit has an eccentricity of 0.19 and an inclination of 6° with respect to the ecliptic.[1] 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.[10]
Physical characteristics
Päijänne is classified as both S-type and transitional CX-type asteroid.[3][9]
Lightcurves
In September 2006, a rotational lightcurve of Päijänne was obtained from photometric observations taken by French amateur astronomer Laurent Bernasconi. The lightcurve analysis gave a well-defined rotation period of 8.8448 hours with a change in brightness of 0.50 magnitude (U=3).[8]
Diameter and albedo
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.[4][5][6][7] The Collaborative Asteroid Lightcurve Link derives an albedo of 0.0638 and a diameter of 26.36 kilometers with an absolute magnitude of 11.5.[3]
Naming
This minor planet was named for Finland's second largest lake, Päijänne, located in south-central Finland, and more than a thousand square kilometers in size.[2] The official naming citation was published by the Minor Planet Center on 20 February 1976 (M.P.C. 3929).[11]
^ abcdUsui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; et al. (October 2011). "Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey". Publications of the Astronomical Society of Japan. 63 (5): 1117–1138. Bibcode:2011PASJ...63.1117U. doi:10.1093/pasj/63.5.1117. (online, AcuA catalog p. 153)