| Discovery[1] | |
|---|---|
| Discovered by | E. F. Helin |
| Discovery site | Palomar Obs. |
| Discovery date | 8 November 1977 |
| Designations | |
| (2099) Opik | |
Named after | Ernst Öpik (Estonian astronomer)[2] |
| 1977 VB · 1977 UL2 | |
| Mars-crosser[1][3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 60.26 yr (22,009 days) |
| Aphelion | 3.1370AU |
| Perihelion | 1.4710 AU |
| 2.3040 AU | |
| Eccentricity | 0.3616 |
| 3.50yr (1,277 days) | |
| 148.76° | |
| 0° 16m 54.48s / day | |
| Inclination | 26.966° |
| 218.84° | |
| 159.18° | |
| Earth MOID | 0.4926 AU |
| Physical characteristics | |
| Dimensions | 5.12 km(calculated)[4] 5.17±1.35 km[5] |
| 6.4430±0.0002h[6] 9.3 h[7] | |
| 0.05±0.06[5] 0.057(assumed)[4] | |
| S(Tholen)[1] Ch(SMASS)[1] C(CALL)[4] B–V = 0.690[1] U–B = 0.350[1] | |
| 15.18[1][4] · 15.22[5] | |
2099 Öpik, provisional designation1977 VB, is a dark and eccentricasteroid andMars-crosser from the inner regions of theasteroid belt, approximately 5.1 kilometers in diameter.
The asteroid was discovered on 8 November 1977, by American astronomerEleanor Helin at thePalomar Observatory in California, and named after Estonian astronomerErnst Öpik.[3]
Öpik orbits the Sun in theinner main-belt at a distance of 1.5–3.1 AU once every 3 years and 6 months (1,277 days). Its orbit has aneccentricity of 0.36 and aninclination of 27° with respect to theecliptic.[1] The first usedprecovery was taken at the discovering observatory in 1970, extending the asteroid'sobservation arc by 7 years prior to its discovery.[3]
Originally, the asteroid'sspectral type was that of a brightS-type asteroid in theTholen classification. More recently, it has been characterized as a dark Ch-type, a hydrated subtype of the carbonaceousC-type asteroids in theSMASS classification, which is in agreement with its lowalbedo (below).[1]
According to the survey carried out by NASA'sWide-field Infrared Survey Explorer with its subsequentNEOWISE mission,Öpik measures 5.17 kilometers in diameter and its surface has analbedo of 0.05.[5] TheCollaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 5.12 kilometers with anabsolute magnitude of 15.18.[4]
In 2005, a photometriclightcurve analysis by several astronomers includingPierre Antonini, rendered arotation period of6.4430±0.0002 hours and with a brightness amplitude of 0.21 inmagnitude (U=2),[6] superseding the results of an observation from the 1990s that gave a longer period of 9.3 hours (U=2).[7]
Thisminor planet was named after Estonian astronomer and astrophysicist,Ernst Öpik (1893–1985), who has influenced many fields of astronomy during his 60-year long career. He is noted for developing the discipline ofstatisticalcelestial mechanics and for methods to estimate the lifetimes of planet-crossing asteroids. In the early 1950s, he calculated the impact probability of Mars-crossing asteroids with Mars, and concluded that a search forimpact craters on Mars would be a fruitful. Fourteen years later, Martian craters were discovered byMariner 4.[2] The officialnaming citation was published by theMinor Planet Center on 1 November 1978 (M.P.C. 4548).[8]
