9951 Tyrannosaurus
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 Orbit of Tyrannosaurus (blue), with the inner planets and Jupiter (outermost) | |
| Discovery[1] | |
|---|---|
| Discovered by | E. W. Elst |
| Discovery site | La Silla Obs. |
| Discovery date | 15 November 1990 |
| Designations | |
| (9951) Tyrannosaurus | |
| Pronunciation | /tɪˌrænəˈsɔːrəs/[2] |
Named after | Tyrannosaurus (theropod dinosaur)[3] |
| 1990 VK5 · 1974 OG1 1992 EZ5 | |
| main-belt · (inner) Vesta[4] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 42.53 yr (15,534 days) |
| Aphelion | 2.7243 AU |
| Perihelion | 2.1283 AU |
| 2.4263 AU | |
| Eccentricity | 0.1228 |
| 3.78 yr (1,380 days) | |
| 155.31° | |
| 0° 15m 38.88s / day | |
| Inclination | 7.4000° |
| 133.42° | |
| 153.36° | |
| Physical characteristics | |
| Dimensions | 17 km[5] |
| S[6] | |
| 14.2[1] | |
9951 Tyrannosaurus, provisional designation 1990 VK5, is a stony Vestian asteroid from the inner regions of the asteroid belt, approximately 17 kilometers in diameter. It was discovered on 15 November 1990, by Belgian astronomer Eric Elst at ESO's La Silla Observatory in northern Chile.[7] It was named after Tyrannosaurus, a genus of dinosaurs.[3]
Based on the Hierarchical Clustering Method, Tyrannosaurus is a member of the Vesta family (401),[4] which is named after its parent 4 Vesta, the main belt's second-largest and second-most-massive body after Ceres.
Tyrannosaurus orbits the Sun in the inner main-belt at a distance of 2.1–2.7 AU once every 3 years and 9 months (1,380 days). Its orbit has an eccentricity of 0.12 and an inclination of 7° with respect to the ecliptic.[1] It was first identified as 1974 OG1 at El Leoncito in 1974, extending the body's observation arc by 16 years prior to its official discovery observation at La Silla.[7]
Physical characteristics
Tyrannosaurus has been characterized as a common S-type asteroid.[6] The overall spectral type for members of the Vesta family is that of a V-type.[8]: 23 Vestian asteroids have a composition akin to cumulate eucrites (HED meteorites) and are thought to have originated deep within 4 Vesta's crust, possibly from the Rheasilvia crater, a large impact crater on its southern hemisphere near the South pole, formed as a result of a subcatastrophic collision.[9]
Diameter and albedo
According to the survey carried out by the Infrared Astronomical Satellite IRAS, Tyrannosaurus measures 17 kilometers in diameter.[5] Spectroscopic observations indicate that it is a stony S-type asteroid, the most abundant spectral class of asteroids in the inner main-belt.[6] It has an absolute magnitude of 14.2.[1]
Lightcurves
As of 2017, no rotational lightcurve of Tyrannosaurus has been obtained. The asteroid's rotation period, poles and shape remain unknown.[10]
