2015 FJ345

Trans-Neptunian object December 2018 yes 2015 FJ 345 #C2E0FF Mauna Kea Obs. Mauna Kea Obs.(first observed only) 17 March 2015 2015 FJ 345 TNO detached SDO distant 27 April 2019 (JD 2458600.5) 6 4 1.13 yr (413 d) 74.837 AU 50.785 AU 62.811 AU 0.1915 497.81 yr (181,824 d) 58.879° 0.0020 ms / day 34.973° 37.881° 77.511° 117 km 125 25 km 0.09 (assumed) 25.74 7.9 2015 FJ 345 is a trans-Neptunian object and detached object, located in the scattered disc, the outermost region of the Solar System. It was first observed on 17 March 2015, by a team led by American astronomer Scott Sheppard at the Mauna Kea Observatories, in Hawaii, United States. With its perihelion of almost 51 AU, it belongs to a small and poorly understood group of very distant objects with moderate eccentricities. The object measures approximately 120 km mi off us in diameter. Discovery 2015 FJ 345 was first observed on 17 March 2015, by a team of astronomers led by Scott Sheppard of the Carnegie Institution for Science as part of the survey for distant Solar System objects beyond the Kuiper Cliff using the new wide-field cameras on the Subaru and Cerro Tololo Inter-American Observatory (CTIO) telescopes. Orbit and classification thumb|left|200px|The object is located in the "gap", a poorly understood region. 2015 FJ 345 orbits the Sun at a distance of 50.8–74.8 AU once every 497 years and 10 months (181,824 days; semi-major axis of 62.81 AU). Its orbit has an eccentricity of 0.19 and an inclination of 35° with respect to the ecliptic. The object belongs to the same group as 2004 XR 190 ("Buffy"), 2014 FC 72, 2014 FZ 71 and 2015 KQ 174 (also see diagram). With an orbital period of 498 years, it seems to be a resonant trans-Neptunian object in a 1:3 resonance with Neptune,12 as several other objects, but with a lower eccentricity (0.19 instead of more than 0.60) and higher perihelia (at 50.8 AU rather than 31–41 AU). Considered a scattered and detached object, 2015 FJ 345 is particularly unusual as it has an unusually circular orbit for a scattered-disc object (SDO). Although it is thought that traditional scattered-disc objects have been ejected into their current orbits by gravitational interactions with Neptune, the low eccentricity of its orbit and the distance of its perihelion (SDOs generally have highly eccentric orbits and perihelia less than 38 AU) seems hard to reconcile with such celestial mechanics. This has led to some uncertainty as to the current theoretical understanding of the outer Solar System. The theories include close stellar passages, unseen planet/rogue planets/planetary embryos in the early Kuiper belt, and resonance interaction with an outward-migrating Neptune. The Kozai mechanism is capable of transferring orbital eccentricity to a higher inclination. Physical characteristics 2015 FJ 345 has a diameter estimated between 117 and 125 kilometers. References 30em 2016-05-03 last obs. JPL Small-Body Database Browser: (2015 FJ345) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3753792 Jet Propulsion Laboratory 12 December 2018 2015 FJ345 Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=2015+FJ345 12 December 2018 2015 FJ345 – Ephemerides AstDyS-2, Asteroids Dynamic Site, Department of Mathematics, University of Pisa, Italy https://newton.spacedys.com/astdys/index.php?pc=1.1.3.0&n=2015FJ345 12 December 2018 List of Known Trans-Neptunian Objects Johnston's Archive 7 October 2018 Johnston Wm. Robert https://www.johnstonsarchive.net/astro/tnoslist.html 12 December 2018 Jewitt, David, Morbidelli, Alessandro, & Rauer, Heike. (2007). Trans-Neptunian Objects and Comets: Saas-Fee Advanced Course 35. Swiss Society for Astrophysics and Astronomy. Berlin: Springer. 3-540-71957-1. Patryk Sofia Lykawka Tadashi Mukai July 2007 Dynamical classification of trans-neptunian objects: Probing their origin, evolution, and interrelation Icarus 189 1 213–232 2007Icar..189..213L 10.1016/j.icarus.2007.01.001 R. L. Allen B. Gladman J. J. Kavelaars J.-M. Petit J. W. Parker P. Nicholson March 2006 Discovery of a Low-Eccentricity, High-Inclination Kuiper Belt Object at 58 AU The Astrophysical Journal 640 1 L83–L86 2006ApJ...640L..83A 10.1086/503098 astro-ph/0512430 15588453 (Discovery paper) Scott S. Sheppard Chadwick Trujillo David J. Tholen July 2016 Beyond the Kuiper Belt Edge: New High Perihelion Trans-Neptunian Objects with Moderate Semimajor Axes and Eccentricities The Astrophysical Journal Letters 825 1 7 2016ApJ...825L..13S 10.3847/2041-8205/825/1/L13 1606.02294 118630570 free External links List Of Centaurs and Scattered-Disk Objects, Minor Planet Center List of Known Trans-Neptunian Objects, Johnston's Archive 2015FJ345 3753792 # Category:Minor planet object articles (unnumbered) # 20150317 Category:Trans-Neptunian objects in a 1:3 resonance