(523731) 2014 OK394

Trans-Neptunian object February 2018 yes (523731) 2014 OK 394 #C2E0FF 2014 OK394 DECam 2020-01-22 annotated.png 2014 OK 394 photographed by Cerro Tololo Observatory's Dark Energy Camera on 22 January 2020 20 September 1995 Spacewatch Kitt Peak Obs. (523731) 2014 OK 394 1995 SN 55 3:5 resonantTNOdistant 9 June 2026 (JD 2461200.5) 2 21.10 yr (7,708 days) 49.698 AU 35.528 AU ≈ 4 January 1997 42.613 AU 0.166 278.18 yr 36.246° 0.0035431 ms / day 4.134° 128.550° 250.384° 0 160–280 km (est. 0.08–0.20) 6.2 (523731) 2014 OK 394, also known as 1995 SN 55, is a trans-Neptunian object located in the Kuiper belt. It orbits the Sun in a 3:5 orbital resonance with Neptune, meaning it completes three orbits for every five completed by Neptune. It was discovered by Spacewatch at Kitt Peak, Arizona on 20 September 1995, but astronomers lost track of it for over a decade. It was unknowingly rediscovered by Pan-STARRS in 2010 and was later linked back to Spacewatch's 1995 discovery in 2020. Discovery The object was discovered twice and therefore has two provisional designations. It was first discovered on 20 September 1995 by astronomers Nichole Danzl and Arianna Gleason of the Spacewatch survey at Kitt Peak Observatory in Arizona, United States. However, it was only observed 14 times over 36 days, from 20 September to 26 October 1995. The object was never seen again and thus became a lost minor planet. The Minor Planet Center (MPC) gave it the provisional designation 1995 SN 55 and published the discovery observations on 11 June 1999. Due to the sparse amount of observations, 1995 SN 55's calculated orbit was extremely uncertain. Astronomers had speculated that 1995 SN 55 might either be one of the largest known centaurs, a temporarily brightening object, or a false positive caused by image noise. On 8 October 2010, the object was unknowingly rediscovered by the Pan-STARRS 1 survey at Haleakalā Observatory, Hawaii. Pan-STARRS continued observing the object until 2015, and the MPC later announced its discovery with the provisional designation 2014 OK 394 on 17 July 2016. In 2018, after the object's orbit was securely determined, the MPC assigned the official discovery credit to Pan-STARRS. On 30 November 2020, amateur astronomers S. Deen and K. Ly identified 2014 OK 394 as being the same object as 1995 SN 55. This identification was published by the MPC on 27 January 2021 and the object's discoverer was later changed to Spacewatch. Numbering and naming 2014 OK 394 was numbered by the MPC on 25 September 2018 and received the number 523731 523731 in the minor planet catalog. The provisional designation 1995 SN 55 was added by the MPC on 27 January 2021 after the two discoveries were linked. 2026, it has not been named. Classification and orbit thumb|Orbit diagram of 2014 OK 394 (white) and the outer planets 2014 OK 394 orbits the Sun with an average distance (semi-major axis) of 42.6 astronomical units (AU) and an orbital period of 278 years. It is located in the Kuiper belt, a region of the Solar System beyond Neptune where many other icy minor planets are found. 2014 OK 394's orbit has an eccentricity of 0.17 and an inclination of 4° with respect to the ecliptic plane. Over the course of its orbit, its distance from the Sun ranges from 35.5 AU at perihelion to 49.7 AU at aphelion. 2014 OK 394 is in a 3:5 mean-motion orbital resonance with Neptune, meaning it completes three orbits every time Neptune completes five. Its orbit has a minimum orbit intersection distance approximately 5.8 AU e6km e6mi unit from Neptune's orbital path. Physical characteristics Little is known about 2014 OK 394's physical characteristics. Johnstons Archive estimates a diameter of 217 km mi assuming a geometric albedo of 0.126, whereas Michael E. Brown estimates a diameter of 160 km mi for an assumed albedo of 0.20. A 2024 study led by Audrey Thirouin and Scott Sheppard found that 2014 OK 394 exhibits little variability in brightness over four hours of observations, with a light curve amplitude of roughly 0.05 magnitude. See also Lost minor planet (392741) 2012 SQ 31 – main-belt asteroid originally misidentified as a trans-Neptunian object References 30em 2026-01-21 last obs. JPL Small-Body Database Lookup: 523731 (2014 OK394 = 1995 SN55) https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=1995%20SN55 Jet Propulsion Laboratory https://web.archive.org/web/20201130231114/http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3137692 30 November 2020 live 2026-08-01 dmy-all (523731) = 1995 SN55 = 2014 OK394 http://www.minorplanetcenter.net/db_search/show_object?object_id=523731 Minor Planet Center International Astronomical Union https://web.archive.org/web/20201130231206/http://www.minorplanetcenter.net/db_search/show_object?object_id=1995+SN55 30 November 2020 live 2026-08-01 JPL Horizons On-Line Ephemeris for 523731 (2014 OK394 = 1995 SN55) http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=ab&sstr=523731 JPL Horizons On-Line Ephemeris System Jet Propulsion Laboratory 10 February 2021Ephemeris Type: OBSERVER, Target Body: 523731 (2014 OK394), Observer Location: Sun (body center) [500@10], Table Settings: QUANTITIES=20. Observer range(Perihelion occurs when deldot changes from negative to positive.) MPEC 1999-L25 : 1995 SN55, 1998 TF35 https://minorplanetcenter.net//iau/mpec/J99/J99L25.html Brian G. Marsden Minor Planet Electronic Circular Minor Planet Center 11 June 1999 1999-L25 30 November 2020 1999MPEC....L...25D 1995-10-26 last obs. JPL Small-Body Database Browser: (1995 SN55) http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3137692 Jet Propulsion Laboratory https://web.archive.org/web/20201130231114/http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3137692 30 November 2020 dead 24 February 2021(Archive of 36 day observation arc of 1995 SN 55) How many dwarf planets are there in the outer solar system? http://web.gps.caltech.edu/~mbrown/dps.html California Institute of Technology Michael E. Brown 23 February 2021 24 February 2021 Conversion of Absolute Magnitude to Diameter for Minor Planets http://www.physics.sfasu.edu/astro/asteroids/sizemagnitude.html Dan Bruton Department of Physics, Engineering, and Astronomy Stephen F. Austin State University 24 February 2021 23 July 2011 https://web.archive.org/web/20110723191750/http://www.physics.sfasu.edu/astro/asteroids/sizemagnitude.html dead List of Known Trans-Neptunian Objects http://www.johnstonsarchive.net/astro/tnoslist.html Wm. Robert Johnston Johnston's Archive 18 August 2020 24 February 2021 MPEC 2016-O154 : 2014 OK394 https://minorplanetcenter.net/mpec/K16/K16OF4.html Minor Planet Electronic Circular Minor Planet Center 17 July 2016 23 February 2021 2016MPEC....O..154G etal Gibson B. Goggia T. Primak N. Schultz A. Willman M. Chambers K. 2016-O154 A 300-kilometre space rock has vanished since we saw it in 1995 https://www.newscientist.com/article/2151431-a-300-kilometre-space-rock-has-vanished-since-we-saw-it-in-1995/ Joshua Sokol New Scientist 25 October 2017 24 February 2021 M.P.C. 111781 https://minorplanetcenter.net/iau/ECS/MPCArchive/2018/MPC_20180925.pdf Minor Planet Circular Minor Planet Center 25 September 2018 23 February 2021 1995 SN55 https://groups.io/g/mpml/topic/1995_sn55/78619332 Sam Deen groups.io 30 November 2020 23 February 2021 M.P.C. 127300 https://minorplanetcenter.net/iau/ECS/MPCArchive/2021/MPC_20210127.pdf Minor Planet Circular Minor Planet Center 27 January 2021 23 February 2021 Thirouin Audrey Sheppard Scott S. April 2024 Rotational Study of 5:3 and 7:4 Resonant Objects within the Main Classical Trans-Neptunian Belt The Planetary Science Journal 5 4 84 free 10.3847/PSJ/ad2933 2402.05269 2024PSJ.....5...84T External links A 300-kilometre space rock has vanished since we saw it in 1995, Joshua Sokol, New Scientist, 25 October 2017 2523731 (523727) 2014 NW65 523731 (523731) 2014 OK 394 (523759) 2014 WK509 523731 523731 523731 19950920 20101008 523731