| Discovery[1] | |
|---|---|
| Discovered by | N. Chernykh |
| Discovery site | Crimean Astrophysical Obs. |
| Discovery date | 13 August 1985 |
| Designations | |
| (4786) Tatianina | |
Named after | Tatiana Somova[1] (Friend of discoverer) |
| 1985 PE2 · 1948 GA 1970 KF · 1984 EV1 1984 FM1 | |
| main-belt[1][2] · (inner)[3] background[4] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 47.10yr (17,202 d) |
| Aphelion | 2.8145AU |
| Perihelion | 1.9011 AU |
| 2.3578 AU | |
| Eccentricity | 0.1937 |
| 3.62 yr (1,322 d) | |
| 83.900° | |
| 0° 16m 19.92s / day | |
| Inclination | 7.2560° |
| 115.77° | |
| 118.27° | |
| Knownsatellites | 1(D:0.61 kmP:21.67 h)[3][5][6][a] |
| Physical characteristics | |
| 3.282±0.197 km[7][8] 3.475 km[9] 3.48 km(taken)[3] | |
| 2.9227±0.0001 h[a] 2.9227 h[6] 2.9228±0.0003 h[10] | |
| 0.4763[9] 0.5136±0.1593[8] 0.514±0.159[7] | |
| SMASS =Xc[2] · E[8] | |
| 13.3[2] 13.31±0.1(R)[a] 13.46±0.20[11] 13.718±0.1[3][9] 13.76[8] | |
4786 Tatianina, provisional designation1985 PE2, is a bright backgroundasteroid and synchronousbinary system from the inner regions of theasteroid belt, approximately 3.4 kilometers (2.1 miles) in diameter. It was discovered on 13 August 1985, by Soviet astronomerNikolai Chernykh at theCrimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula.[1] It was named after Tatiana Somova, a friend of the discoverer. TheE-/Xc-subtype has a shortrotation period of 2.9 hours.[3] Its sub-kilometerminor-planet moon was discovered on 20 March 2006 and announced the following month.[5][6]
Tatianina is a non-family asteroid from the main belt'sbackground population.[4] It orbits the Sun in theinner asteroid belt at a distance of 1.9–2.8 AU once every 3 years and 7 months (1,322 days;semi-major axis of 2.36 AU). Its orbit has aneccentricity of 0.19 and aninclination of 7° with respect to theecliptic.[2]
The asteroid was first observed as1948 GA at theAlgiers Observatory in April 1948. The body'sobservation arc begins at Nauchnij in May 1970 as1970 KF, more than 15 years prior to its official discovery observation.[1]
In theSMASS classification,Tatianina is a Xc-subtype that transitions from theX-type to the carbonaceousC-type asteroids.[2] It has also been characterized as a brightE-type by theWide-field Infrared Survey Explorer (WISE).[3][8]
Several rotationallightcurves ofTatianina have been obtained fromphotometric observations since 2003 (U=3/2+/3).[6][10][a] Analysis of the best-rated lightcurve from March 2003, during which a satellite was also discovered(see below), gave arotation period of 2.9227 hours with a brightness amplitude of 0.19 and 0.20magnitude (U=3/3).[3][6][a]
According to the survey carried out by theNEOWISE mission of NASA's WISE telescope,Tatianina measures between 3.282 and 3.475 kilometers in diameter and its surface has an exceptionally highalbedo of 0.4763 to 0.514.[7][8][9] TheCollaborative Asteroid Lightcurve Link adopts the revised WISE-data byPetr Pravec, that is an albedo of 0.4763 and rounded diameter of 3.48 kilometers based on anabsolute magnitude of 13.718.[3]
During the photometric observations byDonald Pray, Petr Pravec and collaborators in March 2006, it was revealed thatTatianina is a synchronousbinary asteroid with aminor-planet moon orbiting it every 21.67 hours at an estimated average distance of6.6 km. The discovery was announced on 11 April 2006.[6] The mutualoccultation events suggest the presence of a satellite with an estimated diameter of610±10 meters or 19% the size of its primary.[3][5][a]
Thisminor planet was numbered on 28 April 1991.[5] It was named by the discoverer after Tatiana Aleksandrovna Somova, a nursery-school teacher inSaint Petersburg, Russia.[1] The official naming citation was published by theMinor Planet Center on 5 March 1996 (M.P.C. 26762).[12]
