4185 Phystech
Main-belt asteroid
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4185 Phystech, provisional designation 1975 ED, is a Florian or background asteroid from the inner regions of the asteroid belt, approximately 6 kilometers (4 miles) in diameter. It was discovered on 4 March 1975, by Soviet astronomer Tamara Smirnova at the Crimean Astrophysical Observatory in Nauchnij, on the Crimean peninsula.[1] The presumed S-type asteroid has a rotation period of 4.67 hours. It is named in honor of the Moscow Institute of Physics and Technology ("PhysTech") on its 50th anniversary.[1]
| Discovery[1] | |
|---|---|
| Discovered by | T. Smirnova |
| Discovery site | Crimean Astrophysical Obs. |
| Discovery date | 4 March 1975 |
| Designations | |
| (4185) Phystech | |
Named after | Moscow Institute of Physics and Technology[1] |
| 1975 ED · 1982 KD 1982 KH4 · 1988 BT | |
| main-belt[1][2] · (inner) background[3][4] · Flora[5] | |
| Orbital characteristics[2] | |
| Epoch 23 March 2018 (JD 2458200.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 64.48 yr (23,550 d) |
| Aphelion | 2.4339 AU |
| Perihelion | 2.0008 AU |
| 2.2174 AU | |
| Eccentricity | 0.0977 |
| 3.30 yr (1,206 d) | |
| 311.69° | |
| 0° 17m 54.6s / day | |
| Inclination | 2.2303° |
| 265.78° | |
| 320.99° | |
| Physical characteristics | |
| 5.93 km (calculated)[5] | |
| 4.66883±0.00014 h[6] 4.66904±0.00003 h[6] | |
| 0.24 (assumed)[5] | |
| S (assumed)[5] | |
| 13.3[2][5] | |
Orbit and classification
Phystech is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements.[3][4] Based on osculating Keplerian orbital elements, the asteroid has also been classified as a member of the Flora family (402), a giant asteroid family and the largest family of stony asteroids in the main-belt.[5]
It orbits the Sun in the inner asteroid belt at a distance of 2.0–2.4 AU once every 3 years and 4 months (1,206 days; semi-major axis of 2.22 AU). Its orbit has an eccentricity of 0.10 and an inclination of 2° with respect to the ecliptic.[2] The body's observation arc begins with a precovery taken at Palomar Observatory in October 1953, more than 21 years prior to its official discovery observation at Nauchnij.[1]
Physical characteristics
Phystech is an assumed stony S-type asteroid, based on its family classification.[5]
Rotation period
In March and April 2008, two rotational lightcurves of Phystech were obtained from photometric observations by American astronomers at LPL and Calvin College (H62). Lightcurve analysis gave a well-defined rotation period of 4.66883 and 4.66904 hours with a brightness amplitude of 0.53 and 0.41 magnitude, respectively (U=3/3).[6]
Diameter and albedo
The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.24 – derived from 8 Flora, the parent body of the Flora family – and calculates a diameter of 5.93 kilometers based on an absolute magnitude of 13.3.[5]
Naming
This minor planet was named after the Moscow Institute of Physics and Technology (informally: "PhysTech"; Физтех) on the occasion of its 50th anniversary in 1996, based on a proposal by the Institute of Theoretical Astronomy (ITA) in Saint Petersburg, Russia.[1] The official naming citation was published by the Minor Planet Center on 22 February 1997 (M.P.C. 29143).[7]
