.png) Lightcurve-based 3D-model ofPunkaharju | |
| Discovery[1] | |
|---|---|
| Discovered by | Y. Väisälä |
| Discovery site | Turku Obs. |
| Discovery date | 28 December 1940 |
| Designations | |
| (1659) Punkaharju | |
Named after | Punkaharju(region)[2] |
| 1940 YL · 1930 QB 1937 EB · 1944 RE 1951 EG · 1953 NH 1957 KO · 1958 TS1 | |
| main-belt · (middle)[3] Postrema[4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 86.68 yr (31,660 days) |
| Aphelion | 3.5066AU |
| Perihelion | 2.0646 AU |
| 2.7856 AU | |
| Eccentricity | 0.2588 |
| 4.65yr (1,698 days) | |
| 243.68° | |
| 0° 12m 43.2s / day | |
| Inclination | 16.426° |
| 338.26° | |
| 36.257° | |
| Physical characteristics | |
| Dimensions | 28.010±0.599 km[5] 28.24±1.54 km[6] 31.21±2.9 km[7] 31.41 km(derived)[3] |
| 5.01±0.02h[8] 5.01±0.01 h[9] 5.01327±0.00005 h[10] 5.0138±0.0002 h[11] 5.028±0.007 h[11] | |
| 0.1654±0.035[7] 0.1963(derived)[3] 0.202±0.024[6] 0.271±0.040[5] | |
| SMASS =S[1] · S[3] | |
| 9.80[5] · 9.9[1][3] · 10.1[6][7] · 10.42±0.35[12] | |
1659 Punkaharju, provisional designation1940 YL, is a stony Postremianasteroid from the middle region of theasteroid belt, approximately 30 kilometers in diameter. It was discovered on 28 December 1940, by Finnish astronomerYrjö Väisälä atTurku Observatory in Southwest Finland.[13] It is named for the municipality ofPunkaharju.[2]
Punkaharju is a member of thePostrema family (541),[4] a mid-sized centralasteroid family of little more than 100 members.[14]: 23 TheS-type asteroid orbits the Sun at a distance of 2.1–3.5 AU once every 4 years and 8 months (1,698 days). Its orbit has aneccentricity of 0.26 and aninclination of 16° with respect to theecliptic.[1]Punkaharju was first identified as1930 QB atUccle Observatory in 1930, extending the body'sobservation arc by 10 years prior to its official discovery observation.[13]
Between 2000 and 2011, several rotationallightcurves ofPunkaharju were obtained from photometric observations by astronomersBrian Warner andPierre Antonini. They gave a well-definedrotation period of 5.01 hours with a brightness variation between 0.26 and 0.43magnitude (U=3/3/3).[8][9][11] In addition, a concurring period of 5.01327 hours was published in 2016, using theUppsala Asteroid Photometric Catalogue as the main-data source.[10] French CCD-specialistCyril Cavadore also derived a less secure period of 5.028 hours from his observations in October 2005 (U=2-).[11]
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, the asteroid measures between 28.01 and 31.21 kilometers in diameter, and its surface has analbedo between 0.165 and 0.271.[5][6][7] TheCollaborative Asteroid Lightcurve Link derives an albedo of 0.196 and a diameter of 31.41 kilometers using anabsolute magnitude of 9.9.[3]
Thisminor planet is named for the former municipality ofPunkaharju, anisthmus region in southeastern Finland(also seeKarelian Isthmus).[2] The officialnaming citation was published by theMinor Planet Center on 20 February 1976 (M.P.C. 3933).[15]
