| Discovery[1] | |
|---|---|
| Discovered by | E. Bowell |
| Discovery site | Anderson Mesa Stn. |
| Discovery date | 30 August 1981 |
| Designations | |
| (12999) Toruń | |
Named after | Toruń(Polish city)[2] |
| 1981 QJ2 · 1957 TF 1998 QL8 | |
| main-belt · Baptistina[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 59.49 yr (21,730 days) |
| Aphelion | 2.7036AU |
| Perihelion | 1.8438 AU |
| 2.2737 AU | |
| Eccentricity | 0.1891 |
| 3.43yr (1,252 days) | |
| 168.46° | |
| 0° 17m 15s / day | |
| Inclination | 5.7705° |
| 152.34° | |
| 210.91° | |
| Physical characteristics | |
| Dimensions | 3.523±0.136 km[4][5] 7.96 km(calculated)[3] |
| 3.5521±0.0026h[6] | |
| 0.057(assumed)[3] 0.392±0.028[4][5] | |
| C[3] | |
| 13.773±0.002(R)[6] · 13.8[1] · 13.9[4] · 14.22[3] | |
12999 Toruń, provisional designation1981 QJ2, is a carbonaceous Baptistinaasteroid from the inner regions of theasteroid belt, approximately 8 kilometers in diameter. It was discovered on 30 August 1981, by British–American astronomerEdward Bowell at Lowell Observatory'sAnderson Mesa Station in Flagstaff, Arizona, and named after the Polish city ofToruń.[2]
Toruń is a carbonaceousC-type asteroid and a member of the smallBaptistina family. It orbits the Sun in theinner main-belt at a distance of 1.8–2.7 AU once every 3 years and 5 months (1,252 days). Its orbit has aneccentricity of 0.19 and aninclination of 6° with respect to theecliptic.[1] The firstprecovery was taken atGoethe Link Observatory in 1957, extending the asteroid'sobservation arc by 24 years prior to its discovery.[2]
A rotationallightcurve ofToruń was obtained fromphotometric observations at the U.S.Palomar Transient Factory in December 2009. The provisional lightcurve gave arotation period of3.5521±0.0026 hours with a brightness amplitude of 0.09 inmagnitude (U=1).[6]
According to the survey carried out by theNEOWISE mission of NASA'sWide-field Infrared Survey Explorer,Toruń measures 3.5 kilometers in diameter and its surface has a very highalbedo of 0.39.[4][5] TheCollaborative Asteroid Lightcurve Link (CALL) disagrees with the findings by the space-based mission and assumes a standard albedo for carbonaceous asteroids of 0.057, with a correspondingly larger diameter of 8.0 kilometers with anabsolute magnitude of 14.22.[3] As with1696 Nurmela, another member of the Baptistina family, CALL assumes this asteroid's composition(also seecarbonaceous chondrites) to differ significantly from the much brighter asteroid298 Baptistina, which is considered to be an interloper in its own family.
In 2008, thisminor planet was named after the city ofToruń, Poland. It is the birthplace ofNicolaus Copernicus, significant to Polish and European history, aUNESCO World Heritage listed Old Town, and the main site of theNicolaus Copernicus University, where its observatory at Piwnice, the largest in Poland, is located. The naming followed a suggestion by Polish astronomer T. Michałowski.[2] The approved naming citation was published by theMinor Planet Center 21 March 2008 (M.P.C. 62354).[7]
