Astronomy:385571 Otrera
| Discovery [1][2] | |
|---|---|
| Discovered by | S. S. Sheppard C. Trujillo |
| Discovery site | Las Campanas Obs. |
| Discovery date | 16 October 2004 |
| Designations | |
| (385571) Otrera | |
| Named after | Otrera (Greek mythology)[2] |
| 2004 UP10 | |
| Minor planet category | Neptune trojan · L4 [3] centaur [1] · distant [2] |
| Orbital characteristics [1] | |
| Epoch 4 September 2017 (JD 2458000.5) | |
| Uncertainty parameter 4 | |
| Observation arc | 8.97 yr (3,277 days) |
| |{{{apsis}}}|helion}} | 30.727 AU |
| |{{{apsis}}}|helion}} | 29.327 AU |
| 30.027 AU | |
| Eccentricity | 0.0233 |
| Orbital period | 164.54 yr (60,099 days) |
| Mean anomaly | 355.52° |
| Mean motion | 0° 0m 21.6s / day |
| Inclination | 1.4334° |
| Longitude of ascending node | 34.761° |
| 3.5334° | |
| Physical characteristics | |
| Dimensions | 74 km (est. at 0.10)[4] 100 km[5] |
| Apparent magnitude | 23.3[5] |
| Absolute magnitude (H) | 8.8[1] |
385571 Otrera, provisional designation 2004 UP10, is a Neptune trojan leading Neptune's orbit in the outer Solar System. It was discovered by American astronomers Scott Sheppard and Chad Trujillo at Las Campanas Observatory on 16 October 2004.[2] It measures approximately 100 kilometers in diameter and was the second such body to be discovered after 2001 QR322.[3]
Orbit and classification
Neptune trojans are resonant trans-Neptunian objects in a 1:1 mean-motion orbital resonance with Neptune. These Trojans have a semi-major axis and an orbital period very similar to Neptune's (30.10 AU; 164.8 years).
Otrera belongs to the L4 group, which leads 60° ahead Neptune's orbit. It orbits the Sun with a semi-major axis of 30.027 AU at a distance of 29.3–30.7 AU once every 164 years and 6 months (60,099 days). Its orbit has an eccentricity of 0.02 and an inclination of 1° with respect to the ecliptic.[1]
Physical characteristics
The discoverers estimate that the body has a mean-diameter of 100 kilometers based on a magnitude of 23.3.[5] Based on a generic magnitude-to-diameter conversion, it measures approximately 74 kilometers in diameter using an absolute magnitude of 8.8 and an assumed albedo of 0.10.[4]
Naming
This minor planet was the first Neptune trojan to be named in November 2015. It was named after Otrera, the first Amazonian queen in Greek mythology.[2] The naming scheme is to name these objects after figures related to the Amazons, which was an all-female warrior tribe that fought in the Trojan War on the side of the Trojans against the Greeks.[6]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 "JPL Small-Body Database Browser: 385571 Otrera (2004 UP10)". Jet Propulsion Laboratory. https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2385571.
- ↑ 2.0 2.1 2.2 2.3 2.4 "385571 Otrera (2004 UP10)". Minor Planet Center. https://www.minorplanetcenter.net/db_search/show_object?object_id=385571.
- ↑ 3.0 3.1 "List Of Neptune Trojans". Minor Planet Center. 10 July 2017. http://www.minorplanetcenter.org/iau/lists/NeptuneTrojans.html.
- ↑ 4.0 4.1 "Asteroid Size Estimator". CNEOS/JPL. https://cneos.jpl.nasa.gov/tools/ast_size_est.html.
- ↑ 5.0 5.1 5.2 Lakdawalla, Emily (13 August 2010). "2008 LC15, the first Trojan asteroid discovered in Neptune's L5 point". The Planetary Society. http://www.planetary.org/blogs/emily-lakdawalla/2010/2623.html.
- ↑ "DIVISION F / Working Group for Small Body Nomenclature Working Group for Small Body Nomenclature. THE TRIENNIAL REPORT (2015 Sept 1 - 2018 Feb 15)". IAU. 10 April 2018. https://www.iau.org/static/science/scientific_bodies/working_groups/97/wg-sbn-triennial-report-2015-2018.pdf.
External links
- Scott Sheppard and the hunt for Neptune Trojans on YouTube (time 1:40 min.)
- 385571 Otrera at AstDyS-2, Asteroids—Dynamic Site
- 385571 Otrera at the JPL Small-Body Database
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