2015 RX245
{{Short description|Object on a highly eccentric orbit in the outermost region of the Solar System}}
{{DISPLAYTITLE:{{mp|2015 RX|245}}}}
{{Use dmy dates|date=October 2018}}
{{Infobox planet
| minorplanet = yes
| name = {{mp|2015 RX|245}}
| background = #C2E0FF
| image = Planet_nine-etnos_now-new2.png
| image_scale =
| caption = Orbital diagram of {{mp|2015 RX|245}} and other objects along with hypothetical Planet Nine
| discoverer = {{small|(first observed only)}}
OSSOS
| discovery_site = Mauna Kea Obs.
| discovered = 8 September 2015
| mpc_name = {{mp|2015 RX|245}}
| pronounced =
| named_after =
| mp_category = TNO{{·}}EDDO{{·}}ETNO
distant
| epoch = 27 April 2019 (JD 2458600.5)
| uncertainty = 5
| observation_arc = 1.61 yr (587 d)
| aphelion = 788.22 AU
| perihelion = 45.563 AU
| semimajor = 416.89 AU
| eccentricity = 0.8907
| period = 8512 yr (3,109,107 d)
| mean_anomaly = 358.03°
| mean_motion = {{Deg2DMS|0.0001|sup=ms}} / day
| inclination = 12.144°
| asc_node = 8.5994°
| arg_peri = 65.124°
| neptune_moid = 17.5 AU
| mean_diameter = {{val|245|ul=km}} {{small|(est.)}}{{cite web
|title = How many dwarf planets are there in the outer solar system?
|publisher = California Institute of Technology
|last = Brown |first= Michael E.
|url = http://web.gps.caltech.edu/~mbrown/dps.html
|accessdate = 25 October 2018}}
{{val|255|u=km}} {{small|(est.)}}
| rotation =
| albedo = 0.08 {{small|(assumed)}}
0.09 {{small|(assumed)}}
| spectral_type =
}}
{{mp|2015 RX|245}} is an extreme trans-Neptunian object, detached, on a highly eccentric orbit in the outermost region of the Solar System. It measures approximately {{convert|250|km|mi|abbr=off|sigfig=2|sp=us}} in diameter. It was first observed on 8 September 2015, by astronomers with Outer Solar System Origins Survey using the 3.6-meter Canada–France–Hawaii Telescope at Mauna Kea Observatories, Hawaii, in the United States.
Orbit and classification
File:Planet_nine-etnos_now-close-new.png
{{mp|2015 RX|245}} belongs to a small group of detached objects with perihelion distances of 30 AU or more, and semi-major axes of 150 AU or more. These extreme trans-Neptunian objects (ETNOs) can not reach such orbits without some perturbing object, which lead to the speculation of Planet Nine. It is also denoted at extended detached disc object or extreme distant detached object (EDDO).
It orbits the Sun at a distance of 45.6–788 AU once every 8512 years (3,109,107 days; semi-major axis of 417 AU). Its orbit has an exceptionally high eccentricity of 0.89 and an inclination of 12° with respect to the ecliptic.
The body's observation arc begins with a precovery taken at Mauna Kea on 23 June 2015, or 11 weeks prior to its official first observation. It has a minimum orbital intersection distance with Neptune of 17.5 AU. {{mp|2015 RX|245}} has a similar size and orbit as {{mpl|2013 SY|99}}, as well as close positions to each other at the moment, both about 60 AU from the Sun (see adjunct diagram, in the middle bottom).
{{clear|left}}
Numbering and naming
As of 2018, this minor planet has neither been numbered nor named by the Minor Planet Center. The official discoverers will be defined when the object is numbered.
Physical characteristics
According to American astronomer Michael Brown and to the Johnston's archive, {{mp|2015 RX|245}} measures 128 and 130 kilometers in diameter based on an assumed albedo of 0.09 and 0.08, respectively. As of 2018, no rotational lightcurve has been obtained from photometric observations. The body's rotation period, pole and shape remain unknown.
See also
- {{Section link|List of unnumbered trans-Neptunian objects|2015 RX245}}
References
{{reflist|30em|refs=
|type = 2017-01-30 last obs.
|title = JPL Small-Body Database Browser: (2015 RX245)
|url = https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3775259
|publisher = Jet Propulsion Laboratory
|accessdate = 26 October 2018}}
|title = 2015 RX245
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/db_search/show_object?object_id=2015+RX245
|accessdate = 26 October 2018}}
|title = MPEC 2017-M25 : 2015 RX245
|work = Minor Planet Center
|date = 19 June 2017
|url = https://www.minorplanetcenter.net/mpec/K17/K17M25.html
|accessdate = 26 October 2018}}
|title = List Of Centaurs and Scattered-Disk Objects
|work = Minor Planet Center
|url = https://www.minorplanetcenter.net/iau/lists/t_centaurs.html
|accessdate = 25 October 2018}}
|title = Database Query: objects q>30, a>150
|work = Minor Planet Center
|url = http://minorplanetcenter.net/db_search/show_by_properties?perihelion_distance_min=30&semimajor_axis_min=150
|accessdate = 25 October 2018}}
|title = List of Known Trans-Neptunian Objects
|publisher = Johnston's Archive
|date = 7 October 2018
|url = http://www.johnstonsarchive.net/astro/tnoslist.html
|accessdate = 25 October 2018}}
|title = LCDB Data for (2015+RX245)
|publisher = Asteroid Lightcurve Database (LCDB)
|url = http://www.minorplanet.info/PHP/generateOneAsteroidInfo.php?AstInfo=0%7C2015+RX245
|accessdate = 26 October 2018}}
|display-authors = etal
|last1 = Shankman |first1 = Cory
|title = OSSOS. VI. Striking Biases in the Detection of Large Semimajor Axis Trans-Neptunian Objects
|url = https://pure.qub.ac.uk/portal/en/publications/ossos-vi-striking-biases-in-the-detection-of-large-semimajor-axis-transneptunian-objects(027b7a9c-a171-42b4-9449-9355b0a255d4).html
|date = 2017
|journal = The Astronomical Journal
|volume = 154
|issue = 2
|page = 50
|doi = 10.3847/1538-3881/aa7aed
|arxiv = 1706.05348
|bibcode = 2017AJ....154...50S
|hdl=10150/625487|s2cid = 3535702 |doi-access = free }}
}}
External links
- [https://arxiv.org/abs/1706.05348 OSSOS VI. Striking Biases in the detection of large semimajor axis Trans-Neptunian Objects] 16 Jun 2017
- [https://www.minorplanetcenter.net/iau/lists/t_centaurs.html List Of Centaurs and Scattered-Disk Objects], Minor Planet Center
- {{AstDys|2015RX245}}
- {{JPL small body|id=3775259}}
{{Trans-Neptunian objects}}
{{Small Solar System bodies}}
{{Authority control}}
{{DEFAULTSORT:2015 RX245}}