(85713) 1998 SS49

Asteroid September 2020 yes (85713) 1998 SS 49 #FFC2E0 LINEAR Lincoln Lab's ETS 29 September 1998 (85713) 1998 SS 49 ApolloNEOPHA 4 September 2017 (JD 2458000.5) 0 18.05 yr (6,593 days) 3.1535 AU 0.6940 AU 1.9237 AU 0.6393 2.67 yr (975 days) 359.74° 0.3694 ms / day 10.764° 41.493° 102.47° 0.0023 AU0.9 LD 2.00 0.06 km2.25 km (calculated)3.03 1.49 km3.484 0.789 km 5.370 0.005 hlightcurve-plot-Warner-15.398 0.001 h5.66 0.01 hlightcurve-plot-Warner-2 0.076 0.0390.08 0.120.20 (assumed)0.237 0.018 S (assumed) 15.615.7015.80 0.2916.01 (85713) 1998 SS 49 is an asteroid on an eccentric orbit, classified as a near-Earth object and potentially hazardous asteroid of the Apollo group, approximately 3 km mi off 2 us in diameter. The asteroid was discovered on 29 September 1998, by astronomers of the LINEAR program at Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States. It is one of the largest potentially hazardous asteroids and has a notably low Earth-MOID of less than the distance to the Moon. Orbit and classification 1998 SS 49 is a member of the dynamical Apollo group, which are Earth-crossing asteroids. Apollo asteroids are the largest subgroup of near-Earth objects. It orbits the Sun at a distance of 0.7–3.2 AU once every 2 years and 8 months (975 days; semi-major axis of 1.92 AU). Its orbit has a high eccentricity of 0.64 and an inclination of 11° with respect to the ecliptic. The body's observation arc begins with its official discovery observation at Socorro in September 1998. Close approaches At about absolute magnitude 15.6, 1998 SS 49 is one of the brightest and presumably largest known potentially hazardous asteroid (see PHA-list). It has a very low Earth minimum orbital intersection distance of 0.0023 AU e3km LD unit on. On 26 November 1902, this asteroid made its closest near-Earth encounter since 1900 at a nominal distance of 0.0659 AU e6km LD unit on. The next notable close approach was on 21 November 2022, passing at a nominal distance of 0.141 AU km mi on off. 1998 SS 49 is also a Venus- and Mars-crosser, as it crosses the orbit of Venus and the Red Planet at 0.72 and 1.66 AU, respectively. Physical characteristics 1998 SS 49 is an assumed, stony S-type asteroid. Rotation period In 2014, two rotational lightcurves of 1998 SS 49 were obtained from photometric observations by American astronomer Brian Warner at the CS3–Palmer Divide Station in California (U82). Lightcurve analysis gave a rotation period of 5.370 and 5.66 hours and a brightness variation of 0.18 and 0.06 magnitude, respectively (U=2/2), one of which gave an alternative period solution of 2.686 0.002 hours.lightcurve-plot-Warner-1lightcurve-plot-Warner-2 In April 2016, the EURONEAR lightcurve survey measured a period of 5.398 hours with an amplitude of 0.12 magnitude (U=2). Diameter and albedo Surveys contrast: of the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer. These measure the object as between 2 and 3.484 kilometers lengthways (in diameter) and to have an albedo (optical wavelength reflectivity) between 0.076 and 0.237. The Collaborative Asteroid Lightcurve Link assumes a stony typical albedo of 0.20 to calculate the diameter as 2.25 kilometers and an absolute magnitude of 15.6. Numbering and naming This minor planet was numbered by the Minor Planet Center on 30 August 2004. As of 2018, it has not been named. Notes lightcurve-plot-Warner-1 Lightcurve plot of (85713) 1998 SS 49 – ambiguous rotation period 5.370 0.005 and 2.686 0.002 hours, by B. D. Warner at the CS3–Palmer Divide Station (2014). Quality code of 2. Summary figures at the LCDB and CS3 website. lightcurve-plot-Warner-2 Lightcurve plot of (85713) 1998 SS 49 – rotation period 5.66 0.01 hours, by B. D. Warner at the CS3–Palmer Divide Station (2014). Quality code of 2. Summary figures at the LCDB and CS3 website. References 30em 2016-10-17 last obs. JPL Small-Body Database Browser: 85713 (1998 SS49) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2085713&cad=1 Jet Propulsion Laboratory 18 January 2018 85713 (1998 SS49) Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=85713 18 January 2018 MPC/MPO/MPS Archive Minor Planet Center https://www.minorplanetcenter.net/iau/ECS/MPCArchive/MPCArchive_TBL.html 24 February 2018 List of the Potentially Hazardous Asteroids (PHAs) Minor Planet Center https://www.minorplanetcenter.net/iau/lists/t_phas.html 18 January 2018 6 A. Mainzer T. Grav J. Bauer J. Masiero R. S. McMillan R. M. Cutri R. Walker E. Wright P. Eisenhardt D. J. Tholen T. Spahr R. Jedicke L. Denneau E. DeBaun D. Elsbury T. Gautier S. Gomillion E. Hand W. Mo J. Watkins A. Wilkins G. L. Bryngelson A. Del Pino Molina S. Desai M. Gómez Camus S. L. Hidalgo I. Konstantopoulos J. A. Larsen C. Maleszewski M. A. Malkan J.-C. Mauduit B. L. Mullan E. W. Olszewski J. Pforr A. Saro J. V. Scotti L. H. Wasserman December 2011 NEOWISE Observations of Near-Earth Objects: Preliminary Results The Astrophysical Journal 743 2 17 2011ApJ...743..156M 10.1088/0004-637X/743/2/156 1109.6400 239991 85713 18 January 2018 6 Fumihiko Usui Daisuke Kuroda Thomas G. Müller Sunao Hasegawa Masateru Ishiguro Takafumi Ootsubo Daisuke Ishihara Hirokazu Kataza Satoshi Takita Shinki Oyabu Munetaka Ueno Hideo Matsuhara Takashi Onaka October 2011 Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey Publications of the Astronomical Society of Japan 63 5 1117–1138 2011PASJ...63.1117U 10.1093/pasj/63.5.1117 6 A. Mainzer T. Grav J. Masiero E. Hand J. Bauer D. Tholen R. S. McMillan T. Spahr R. M. Cutri E. Wright J. Watkins W. Mo C. Maleszewski November 2011 NEOWISE Studies of Spectrophotometrically Classified Asteroids: Preliminary Results The Astrophysical Journal 741 2 25 2011ApJ...741...90M 10.1088/0004-637X/741/2/90 1109.6407 35447010 6 C. R. Nugent A. Mainzer J. Bauer R. M. Cutri E. A. Kramer T. Grav J. Masiero S. Sonnett E. L. Wright September 2016 NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos The Astronomical Journal 152 3 12 2016AJ....152...63N 10.3847/0004-6256/152/3/63 1606.08923 free Warner, Brian D. April 2015 Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2014 October–December The Minor Planet Bulletin 42 2 115–127 1052-8091 2015MPBu...42..115W Warner, Brian D. January 2015 Near-Earth Asteroid Lightcurve Analysis at CS3-Palmer Divide Station: 2014 June–October The Minor Planet Bulletin 42 1 41–53 32457969 1052-8091 2015MPBu...42...41W 6 O. Vaduvescu A. Aznar Macias V. Tudor M. Predatu A. Galád S. Gajdos J. Világi H. F. Stevance R. Errmann E. Unda-Sanzana F. Char N. Peixinho M. Popescu A. Sonka R. Cornea O. Suciu R. Toma P. Santos-Sanz A. Sota J. Licandro M. Serra-Ricart D. Morate T. Mocnik M. Diaz Alfaro F. Lopez-Martinez J. McCormac N. Humphries August 2017 The EURONEAR Lightcurve Survey of Near Earth Asteroids Earth 120 2 41–100 2017EM&P..120...41V 10.1007/s11038-017-9506-9 10316/80202 235516956 free 6 Peter Veres Robert Jedicke Alan Fitzsimmons Larry Denneau Mikael Granvik Bryce Bolin Serge Chastel Richard J. Wainscoat William S. Burgett Kenneth C. Chambers Heather Flewelling Nick Kaiser Eugen A. Magnier Jeff S. Morgan Paul A. Price John L. Tonry Christopher Waters November 2015 Absolute magnitudes and slope parameters for 250,000 asteroids observed by Pan-STARRS PS1 - Preliminary results Icarus 261 34–47 2015Icar..261...34V 10.1016/j.icarus.2015.08.007 1506.00762 53493339 External links Asteroid Lightcurve Database (LCDB), query form (info https://web.archive.org/web/20171216050541/http://www.minorplanet.info/lightcurvedatabase.html 16 December 2017 ) Dictionary of Minor Planet Names, Google books 85713 85713 1998SS49 2085713 85713 (85713) 1998 SS 49 085713 085713 085713 19980929