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 | 3.1370 AU |
Perihelion | 1.4710 AU |
2.3040 AU | |
Eccentricity | 0.3616 |
3.50 yr (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±0.0002
h
[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 designation 1977 VB, is a dark and eccentric asteroid and Mars-crosser from the inner regions of the asteroid belt, approximately 5.1 kilometers in diameter.
The asteroid was discovered on 8 November 1977, by American astronomer Eleanor Helin at the Palomar Observatory in California, and named after Estonian astronomer Ernst Öpik. [3]
Öpik orbits the Sun in the inner main-belt at a distance of 1.5–3.1 AU once every 3 years and 6 months (1,277 days). Its orbit has an eccentricity of 0.36 and an inclination of 27 ° with respect to the ecliptic. [1] The first used precovery was taken at the discovering observatory in 1970, extending the asteroid's observation arc by 7 years prior to its discovery. [3]
Originally, the asteroid's spectral type was that of a bright S-type asteroid in the Tholen classification. More recently, it has been characterized as a dark Ch-type, a hydrated subtype of the carbonaceous C-type asteroids in the SMASS classification, which is in agreement with its low albedo (below). [1]
According to the survey carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Öpik measures 5.17 kilometers in diameter and its surface has an albedo of 0.05. [5] The Collaborative Asteroid Lightcurve Link assumes a standard albedo for carbonaceous asteroids of 0.057 and calculates a diameter of 5.12 kilometers with an absolute magnitude of 15.18. [4]
In 2005, a photometric lightcurve analysis by several astronomers including Pierre Antonini, rendered a rotation period of 6.4430±0.0002 hours and with a brightness amplitude of 0.21 in magnitude ( U=2), [6] superseding the results of an observation from the 1990s that gave a longer period of 9.3 hours ( U=2). [7]
This minor 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 of statistical celestial 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 for impact craters on Mars would be a fruitful. Fourteen years later, Martian craters were discovered by Mariner 4. [2] The official naming citation was published by the Minor Planet Center on 1 November 1978 ( M.P.C. 4548). [8]