| Discovery[1] | |
|---|---|
| Discovered by | J. H. Metcalf |
| Discovery site | Taunton, MA, United States |
| Discovery date | 13 September 1907 |
| Designations | |
| (645) Agrippina | |
| Pronunciation | /æɡrɪˈpaɪnə/[2] |
Named after | Agrippīna (the Elder,the Younger)[3] |
| 1907 AG | |
| main-belt (outer) | |
| Orbital characteristics[1] | |
| Epoch 31 July 2016 (JD 2457600.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 108.28 yr (39551 d) |
| Aphelion | 3.6806 AU (550.61 Gm) |
| Perihelion | 2.7439 AU (410.48 Gm) |
| 3.2123 AU (480.55 Gm) | |
| Eccentricity | 0.14581 |
| 5.76yr (2102.9d) | |
| 322.43° | |
| 0° 10m 16.284s / day | |
| Inclination | 7.0434° |
| 0.16657° | |
| 84.246° | |
| Earth MOID | 1.76975 AU (264.751 Gm) |
| Jupiter MOID | 1.61478 AU (241.568 Gm) |
| TJupiter | 3.163 |
| Physical characteristics | |
| Dimensions | 28.00±1.3 km(IRAS:17)[4] 30.86±0.76 km[5] 36.165±0.406 km[6] 29.57±0.58 km[7] 27.94 km(derived)[8] |
| 14.00±0.65km | |
| 32.6 h (1.36 d)[1][9] 34.39±0.05 h[10] | |
| 0.2381±0.025(IRAS:17)[1][4] 0.198±0.011[5] 0.1369±0.0218[6] 0.213±0.028[7] 0.2283(SIMPS)[8] | |
| B–V = 0.871 U–B = 0.412 Tholen =S[1] · S[8] | |
| 9.94[1] | |
645 Agrippina, provisional designation 1907 AG, is a stonyasteroid from the outer region of theasteroid belt, roughly 30 kilometers in diameter. It was discovered by American astronomer reverendJoel Metcalf atTaunton, Massachusetts, USA, on 13 September 1907.[11]
TheS-type asteroid orbits the Sun at a distance of 2.7–3.7 AU once every 5 years and 9 months (2,103 days). Its orbit shows aneccentricity of 0.15 and istilted by 7 degrees to the plane of theecliptic. A photometriclight-curve analysis from the 1980s and a provisional observation in 2004 rendered arotation period of 32.6 and 34.4 hours, respectively.[9][10]
According to the surveys carried out by the Infrared Astronomical Satellite,IRAS, the JapaneseAkari satellite, and the U.S.Wide-field Infrared Survey Explorer with its subsequentNEOWISE mission, the asteroid has a dissimilaralbedo in the range of 0.14 to 0.23, which leads to a varying estimate for its diameter from 28 to 36 kilometers.[4][5][6][7] TheCollaborative Asteroid Lightcurve Link publishes an albedo of 0.23 from an alternative result of the Supplemental IRAS Minor Planet Survey (SIMPS) and derives a slightly lower diameter of 27.9 kilometers.[8]
The minor planet was named for two women ofancient Roman history.Agrippina the Elder (14 BCE – 33) was the daughter of the Roman statesmanMarcus Vipsanius Agrippa, the wife ofGermanicus and the mother of the EmperorCaligula. Her daughter,Agrippina the Younger (15–59 AD) was the mother of EmperorNero. The naming might be influenced by the two letters of the provisional designation1907 AG.[3] In theDictionary of Minor Planet Names, Lutz Schmadel supposes that the name originated from a list of female names from mythology and history, compiled by theAstronomisches Rechen-Institut (ARI) in 1913. The ARI then sent this list to a number of astronomers with the request to name their discoveries in order to avoid confusion, as the number of unnamed minor planet up to number 700 had grown significantly at the time.[12]
