(612093) 1999 LE31

Centaur; damocloid February 2018 yes (612093) 1999 LE 31 #C7FF8F 1999 LE31 asteroid - orbit diagram 01.jpg Orbital diagram of the orbit of 1999 LE 31 LINEAR Lincoln Lab ETS 12 June 1999 (612093) 1999 LE 31 centaurdamocloidunusualdistant 27 April 2019 (JD 2458600.5) 2 19.23 yr (7,022 d) 11.913 AU 4.3396 AU 8.1265 AU 0.4660 23.17 yr (8,462 d) 316.77° 0.0425 ms / day 151.81° 292.12° 32.319° 0.517 AU −1.3090 16.8 4.2 km 0.056 0.026 B–R 1.20 12.5 (612093) 1999 LE 31 is a centaur and damocloid on a retrograde and eccentric orbit from the outer region of the Solar System. It was first observed on 12 June 1999, by astronomers with the LINEAR program at the Lincoln Lab's ETS near Socorro, New Mexico, in the United States. The unusual object measures approximately 17 km mi off 2 us in diameter. Description 1999 LE 31 orbits the Sun at a distance of 4.3–11.9 AU once every 23 years and 2 months (8,462 days; semi-major axis of 8.13 AU). Its orbit has an eccentricity of 0.47 and an inclination of 152° with respect to the ecliptic. It spends most of its orbit located in the outer Solar System between Jupiter and Uranus, and like all centaurs, has an unstable orbit caused by the gravitational influence of the giant planets. Due to this, it must have originated from elsewhere, most likely outside Neptune. It is both a Jupiter and Saturn-crossing minor planet. Of over half a million known minor planets, 1999 LE 31 is one of about 60 that has a retrograde orbit. 1999 LE 31 is approximately 16.8 km in diameter. It came to perihelion (closest approach to the Sun) in December 1998. It was last observed in 2000, and next came to perihelion in February 2022. It was recovered in 2016, is well observed since then, and meanwhile numbered by the Minor Planet Center. Observations This asteroid has been recorded at such observatories as: Lincoln Laboratory (1.0-m f/2.15 reflector + CCD) – location of discovery Dominion Astrophysical Observatory (1.82-m reflector + CCD) Dynic Astronomical Observatory (0.60-m f/3.7 reflector + CCD) European Northern Observatory (1.0-m reflector + CCD) Farpoint (0.30-m Schmidt-Cassegrain + CCD) Kleť Observatory (0.57-m f/5.2 reflector + CCD) McDonald Observatory (0.76-m reflector + CCD) Roque de los Muchachos Observatory (1.0-m reflector + CCD) See also 20461 Dioretsa a.k.a. 1999 LD31 2000 DG 8 List of exceptional asteroids References 30em 2018-08-07 last obs. JPL Small-Body Database Browser: (1999 LE31) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=3021708 Jet Propulsion Laboratory 20 November 2018 (612093) 1999 LE31 Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=612093 7 April 2022 List Of Other Unusual Objects Minor Planet Center 14 November 2018 https://www.minorplanetcenter.net/iau/lists/t_others.html 19 November 2018 List of Known Trans-Neptunian Objects Johnston's Archive 2 January 2022 Johnston Wm. Robert http://www.johnstonsarchive.net/astro/tnoslist.html JPL Small-Body Database Search Engine: Asteroids and i > 90 (deg) JPL Solar System Dynamics http://ssd.jpl.nasa.gov/sbdb_query.cgi?obj_group=all;obj_kind=ast;obj_numbered=all;OBJ_field=0;ORB_field=0;c1_group=ORB;c1_item=Bj;c1_op=%3E;c1_value=90;table_format=HTML;max_rows=200;format_option=comp;c_fields=AcBhBgBjBiBnBsCjCpAi;.cgifields=format_option;.cgifields=obj_kind;.cgifields=obj_group;.cgifields=obj_numbered;.cgifields=ast_orbit_class;.cgifields=table_format;.cgifields=com_orbit_class&query=1&c_sort=AcA 2014-11-15 2010-07-03 1999 LE31 Seiichi Yoshida's Comet Catalog Seiichi Yoshida http://www.aerith.net/comet/catalog/1999LE31/index.html 2014-11-15 15 January 2020 https://web.archive.org/web/20200115011429/http://aerith.net/comet/catalog/1999LE31/index.html dead J. Horner N. W. Evans M. E. Bailey November 2004 Simulations of the population of Centaurs – I. The bulk statistics Monthly Notices of the Royal Astronomical Society 354 3 798–810 2004MNRAS.354..798H 10.1111/j.1365-2966.2004.08240.x free astro-ph/0407400 16002759 External links MPEC 1999-M29 : 1999 LE31, Minor Planet Electronic Circular, Minor Planet Center Yanga R. Fernández, David C. Jewitt, and Scott S. Sheppard, Low Albedos Among Extinct Comet Candidates, May 22, 2001 BAA Comet Section Comets of 1999, Ast.cam.ac.uk 1999 LE31 https://web.archive.org/web/20200115011429/http://aerith.net/comet/catalog/1999LE31/index.html 15 January 2020 – Seiichi Yoshida @ aerith.net Asteroid 1999 LE31 https://web.archive.org/web/20200615003617/https://sbntools.psi.edu/ferret/SimpleSearch/results.action?targetName=1999%20LE31 15 June 2020 , Small Body Data Ferret 1999LE31 612093 (612093) 1999 LE 31 612093 612093 612093 612093 Category:Minor planets with a retrograde orbit 19990612