13963 Euphrates (/juːˈfreɪtiːz/), provisional designation 1991 PT4, is a resonant Griqua asteroid from the outer region of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 3 August 1991, by Belgian astronomer Eric Elst at ESO's La Silla Observatory site in Chile.[5] The asteroid was named after the Euphrates River in the Middle East.[2]
| Discovery[1] | |
|---|---|
| Discovered by | E. W. Elst |
| Discovery site | La Silla Obs. |
| Discovery date | 3 August 1991 |
| Designations | |
| (13963) Euphrates | |
| Pronunciation | /juːˈfreɪtiːz/ |
Named after | Euphrates[2] (river in Mesopotamia) |
| 1991 PT4 · 1997 TO10 | |
| main-belt · (outer)[1] Griqua[3] | |
| Orbital characteristics[1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 0 | |
| Observation arc | 45.98 yr (16,793 days) |
| Aphelion | 4.1853 AU |
| Perihelion | 2.4762 AU |
| 3.3307 AU | |
| Eccentricity | 0.2566 |
| 6.08 yr (2,220 days) | |
| 84.506° | |
| 0° 9m 43.56s / day | |
| Inclination | 0.9360° |
| 227.18° | |
| 129.72° | |
| TJupiter | 3.1090 |
| Physical characteristics | |
| Dimensions | 9±1 km (est. at 0.06)[4] |
| 13.9[1] | |
Orbit and classification
editEuphrates is one of very few bodies located in the 2:1 mean motion resonance with the gas giant Jupiter and belongs to the "marginally unstable" Griqua group.[3]
It orbits the Sun in the outer main-belt at a distance of 2.5–4.2 AU once every 6 years and 1 month (2,220 days). Its orbit has an eccentricity of 0.26 and an inclination of 1° with respect to the ecliptic.[1] A first precovery was taken at Palomar Observatory in 1971, extending the asteroid's observation arc by 20 years prior to its official discovery observation.[5]
Physical characteristics
editBased on an absolute magnitude of 13.9, it measures between 4 and 10 kilometers in diameter, assuming an albedo in the range of 0.05 to 0.25. Since asteroids in the outer main-belt are mostly of a carbonaceous rather than of a silicaceous composition, with low albedos, typically around 0.06, its diameter is likely to be between 8 and 10 kilometers.[4]
As of 2017, Euphrates' effective size, its composition and albedo, as well as its rotation period and shape remain unknown.[1][6]
Naming
editThis minor planet was named after the Euphrates river, that flows through northern Syria and Iraq.[2]
It is one of the most historically important rivers of Western Asia. The Tigris–Euphrates river system, a major river system, is formed when the two rivers combine at Al Qurnah. The minor planet 13096 Tigris is named after the other river of this system.[2] The approved naming citation was published by the Minor Planet Center on 6 August 2003 (M.P.C. 49280).[7]
References
edit- ^ a b c d e f "JPL Small-Body Database Browser: 13963 Euphrates (1991 PT4)" (2017-03-17 last obs.). Jet Propulsion Laboratory. Retrieved 5 July 2017.
- ^ a b c d Schmadel, Lutz D. (2006). "(13963) Euphrates [3.32, 0.26, 0.9]". Dictionary of Minor Planet Names – (13963) Euphrates, Addendum to Fifth Edition: 2003–2005. Springer Berlin Heidelberg. p. 82. doi:10.1007/978-3-540-34361-5_818. ISBN 978-3-540-34360-8.
- ^ a b Roig, F.; Nesvorný, D.; Ferraz-Mello, S. (September 2002). "Asteroids in the 2 : 1 resonance with Jupiter: dynamics and size distribution". Monthly Notices of the Royal Astronomical Society. 335 (2): 417–431. Bibcode:2002MNRAS.335..417R. doi:10.1046/j.1365-8711.2002.05635.x.
- ^ a b "Absolute Magnitude (H)". NASA/JPL. Archived from the original on 2 March 2001. Retrieved 7 April 2016.
- ^ a b "13963 Euphrates (1991 PT4)". Minor Planet Center. Retrieved 7 April 2016.
- ^ "LCDB Data for (13963) Euphrates". Asteroid Lightcurve Database (LCDB). Retrieved 5 July 2017.
- ^ "MPC/MPO/MPS Archive". Minor Planet Center. Retrieved 19 May 2016.
External links
edit- (13963) Euphrates at AstDyS, University of Pisa
- Asteroid Lightcurve Database (LCDB), query form (info Archived 16 December 2017 at the Wayback Machine)
- Dictionary of Minor Planet Names, Google books
- Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
- Discovery Circumstances: Numbered Minor Planets (10001)-(15000) – Minor Planet Center
- 13963 Euphrates at AstDyS-2, Asteroids—Dynamic Site
- 13963 Euphrates at the JPL Small-Body Database
