(508338) 2015 SO20

Trans-Neptunian object June 2017 yes #C2E0FF (508338) 2015 SO 20 M. E. Schwamb La Silla Obs. 8 October 2010 2010 TF 182 (508338) 2015 SO 20 TNOE-SDOdistantdetachedextreme 4 September 2017 (JD 2458000.5) 2 6.96 yr (2,543 days) 290.09 AU 33.164 AU 161.63 AU 0.7948 2054.81 yr (750,519 d) 0.0032° 0.0005 ms / day 23.451° 33.619° 354.80° 221 km (calculated)222 km (calculated) Prominent water (H 2 O/"bowl" type)6 0.08 (assumed)0.09 (assumed) 6.56.7 (508338) 2015 SO 20 is an extreme trans-Neptunian object and extended scattered disc object from the outermost region of the Solar System, approximately 220 km mi off us in diameter. Description 2015 SO 20 was first observed as 2010 TF 182 on 8 October 2010, by American astronomer Megan Schwamb at ESO's La Silla Observatory in northern Chile. It has also been observed as 2015 SO 20 during the Calar Alto TNO Survey (Z79) at the Calar Alto Observatory, Spain, on 20 September 2015. It orbits the Sun at a distance of 33.2–290.1 AU once every 2054 years and 9 months (semi-major axis of 161 AU). Its orbit has an eccentricity of 0.79 and an inclination of 23° with respect to the ecliptic. Extended scattered disc It is one of a small number of detached objects with perihelion distances of 30 AU or more, and semi-major axes of 150 AU or more. Such objects can not reach such orbits without some perturbing object, which leads to the speculation of Planet Nine. Physical characteristics Based on an absolute magnitude of 6.5 and an assumed albedo of 0.09, Johnston's Archive calculated a mean-diameter of 222 kilometers. Michael Brown estimates an albedo of 0.08 with a diameter of 221 kilometers using an absolute magnitude of 6.7. See also Planets beyond Neptune References 30em 2017-09-24 last obs. JPL Small-Body Database Browser: 508338 (2015 SO20) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3731294 Jet Propulsion Laboratory 14 October 2017 (508338) 2015 SO20 Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=2015+SO20 14 October 2017 List of known Trans-Neptunian Objects Johnston's Archive http://www.johnstonsarchive.net/astro/tnoslist.html 14 October 2017 How many dwarf planets are there in the outer solar system? California Institute of Technology Michael E. Brown http://web.gps.caltech.edu/~mbrown/dps.html 9 December 2017 List Of Centaurs and Scattered-Disk Objects Minor Planet Center http://www.minorplanetcenter.org/iau/lists/Centaurs.html 14 October 2017 minorplanetcenter.net: q>30, a>150 etal Noemí Pinilla-Alonso Rosario Brunetto Mário N. De Prá Bryan J. Holler Elsa Hénault Ana Carolina de Souza Feliciano A JWST/DiSCo-TNOs portrait of the primordial Solar System through its trans-Neptunian objects https://hal.science/hal-04961629v1/file/s41550-024-02433-2.pdf Nature Astronomy December 2024 9 2 230–244 10.1038/s41550-024-02433-2 2025NatAs...9..230P 274932942 External links List Of Centaurs and Scattered-Disk Objects, Minor Planet Center List of known Trans-Neptunian Objects, Johnston's Archive Discovery Circumstances: Numbered Minor Planets (505001)-(510000) – Minor Planet Center 508338 508338 (508338) 2015 SO 20 508338 508338 20101008