| Discovery[1] | |
|---|---|
| Discovered by | Y. Väisälä |
| Discovery site | Turku Observatory |
| Discovery date | 9 September 1939 |
| Designations | |
| (1535) Päijänne | |
| Pronunciation | pæi(j)ænːe |
Named after | Lake Päijänne(Finland)[2] |
| 1939 RC · 1933 QE1 1944 OA · 1956 XB 1985 XE2 · A916 OB | |
| main-belt · (outer)[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 83.77 yr (30,598 days) |
| Aphelion | 3.7718AU |
| Perihelion | 2.5586 AU |
| 3.1652 AU | |
| Eccentricity | 0.1916 |
| 5.63yr (2,057 days) | |
| 23.100° | |
| 0° 10m 30s / day | |
| Inclination | 6.0561° |
| 264.79° | |
| 39.922° | |
| Physical characteristics | |
| Dimensions | 23.836±0.206 km[4] 25.518±0.187 km[5] 26.12±0.42 km[6] 26.36 km(derived)[3] 26.72±1.0 km[7] |
| 8.8448±0.0007h[8] | |
| 0.0638(derived)[3] 0.1299±0.011[7] 0.140±0.005[6] 0.1430±0.0230[5] 0.164±0.031[4] | |
| CX[9] · S[3] | |
| 10.7[5][6][7] · 11.44±0.09[9] · 11.5[1][3] | |
1535 Päijänne (/pæi(j)ænːe/; provisional designation1939 RC) is anasteroid from the outer region of theasteroid belt, approximately 25 kilometers in diameter. It was discovered on 9 September 1939, by Finnish astronomerYrjö Väisälä at theTurku Observatory in Southwest Finland.[10] It was later named forLake Päijänne.[2]
Päijänne orbits the Sun in theouter main-belt at a distance of 2.6–3.8 AU once every 5 years and 8 months (2,057 days). Its orbit has aneccentricity of 0.19 and aninclination of 6° with respect to theecliptic.[1] It was first identified asA916 OB atSimeiz Observatory in 1916. The body'sobservation arc begins 6 years prior to its official discovery with its identification as1933 QE1 atHeidelberg Observatory.[10]
Päijänne is classified as bothS-type and transitional CX-type asteroid.[3][9]
In September 2006, a rotationallightcurve of Päijänne was obtained from photometric observations taken by French amateur astronomerLaurent Bernasconi. The lightcurve analysis gave a well-definedrotation period of 8.8448 hours with a change in brightness of 0.50magnitude (U=3).[8]
According to the surveys carried out by the Infrared Astronomical SatelliteIRAS, the JapaneseAkari satellite, and NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission, Päijänne measures between 23.836 and 26.72 kilometers in diameter, and its surface has analbedo between 0.1299 and 0.164.[4][5][6][7] TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.0638 and a diameter of 26.36 kilometers with anabsolute magnitude of 11.5.[3]
Thisminor 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 officialnaming citation was published by theMinor Planet Center on 20 February 1976 (M.P.C. 3929).[11]
