1796 Riga

Main-belt asteroid October 2019 yes 1796 Riga #D6D6D6 16 May 1966 N. Chernykh Crimean Astrophysical Obs. (1796) Riga 1966 KB1935 GE1941 FC 11947 GA1950 TF 21953 GW1960 JAA907 TGA907 UD Riga (capital city) main-belt(outer) 4 September 2017 (JD 2458000.5) 0 66.06 yr (24,129 days) 3.5474 AU 3.1668 AU 9 August 2027Perihelion 3.3571 AU 0.0567 6.15 yr (2,247 days) 142.11° 0.1602 ms / day 22.585° 186.73° 25.620° 66.2 6.6 km68.089 1.037 km68.167 0.298 km71 7 km73.83 1.8 km85.79 1.57 km 10.608 0.002 hlightcurve-plot-200311.0 0.01 h16 h22.226 0.001 h 0.028 0.0010.0376 0.0020.04 0.010.044 0.0050.0442 0.00820.05 0.01 XFCU (Tholen)Cb (SMASS)PCB–V = 0.676U–B = 0.289 9.59 0.409.84 (IRAS:12)9.84 14.3Perihelic opposition (2026–2050) to 16.4 1796 Riga, provisional designation 1966 KB, is a dark asteroid from the outer region of the asteroid belt, approximately 70 kilometers in diameter. It was discovered on 16 May 1966, by Russian astronomer Nikolai Chernykh at the Crimean Astrophysical Observatory in Nauchnyj, on the Crimean peninsula. It is named after the Latvian capital Riga. It came to opposition on 21 January 2026 at apparent magnitude 15.1 in the constellation of Monoceros.2026 opposition Orbit and classification The asteroid orbits the Sun in the outer main-belt at a distance of 3.2–3.5 AU once every 6 years and 2 months (2,247 days). Its orbit has an eccentricity of 0.06 and an inclination of 23° with respect to the ecliptic. The body was first identified as "1907 TG" at the U.S Taunton Observatory (803) in 1907, and its first used precovery was taken at the Goethe Link Observatory in 1953, extending the asteroid's observation arc by 13 years prior to its official discovery observation. It is a member of the Cybele group of asteroids. Spectral type The carbonaceous C-type asteroid is also classified as a very dark and featureless reddish P-type body by the NEOWISE survey of the Wide-field Infrared Survey Explorer (WISE). In the Tholen and SMASS taxonomy, it has a XFCU and Cb subtype, respectively. Diameter and albedo According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and NASA's WISE/NEOWISE mission, the asteroid measures between 66.2 and 85.7 kilometers in diameter and its surface has an albedo between 0.028 and 0.05. The Collaborative Asteroid Lightcurve Link (CALL) agrees with the results obtained by IRAS, adopting a diameter of 73.83 kilometers with an albedo of 0.0376, based on an absolute magnitude of 9.84. Rotation period Several rotational lightcurve for this asteroid were obtained from photometric observations since 1997. They gave a variety of rotation periods from 10.608 to 22.226 hours with inconsistent brightness variations in the range of 0.05 to 0.40 magnitude (U=2/2-/n.a./2).lightcurve-plot-2003 CALL adopts the results of the most observations made by astronomer Julian Oey at the Australian Blue Mountains Observatory (Q68) in March 2014, which gave a period of 22.226 0.001 hours and an amplitude of 0.40 0.05 magnitude (U=2). Naming The minor planet was named after Riga, the capital of Latvia and location of the Astronomical Observatory of the University of Latvia. The name was proposed by Matiss A. Dirikis, who was a member of the observatory at the Latvian State University, and after whom the asteroid 1805 Dirikis is named. The official 1796 naming citation was published by the Minor Planet Center on 25 September 1971 (M.P.C. 3185). Notes lightcurve-plot-2003 Lightcurve plot of 1796 Riga, Palmer Divide Observatory, by B. D. Warner (2003), with a rotation period 10.608 0.002 hours and a brightness amplitude of 0.14 0.02 mag. Summary figures at Collaborative Asteroid Lightcurve Link (CALL) References 30em PRIMASS visits Hilda and Cybele groups De Prá M. N. Pinilla-Alonso N. Carvano J. M. Licandro J. Campins H. Mothé-Diniz T. De León J. Alí-Lagoa V. 1 Icarus 311 35–51 September 2018 1711.02071 2018Icar..311...35D 10.1016/j.icarus.2017.11.012 . 2016-11-04 last obs. JPL Small-Body Database Browser: 1796 Riga (1966 KB) https://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2001796 Jet Propulsion Laboratory 1 July 2017 Dictionary of Minor Planet Names – (1796) Riga Schmadel Lutz D. Springer Berlin Heidelberg 144 2007 978-3-540-00238-3 10.1007/978-3-540-29925-7_1797 (1796) Riga 1796 Riga (1966 KB) Minor Planet Center https://www.minorplanetcenter.net/db_search/show_object?object_id=1796 29 October 2016 Dictionary of Minor Planet Names – Addendum to Fifth Edition (2006–2008) Appendix – Publication Dates of the MPCs Schmadel Lutz D. Springer Berlin Heidelberg 221 978-3-642-01964-7 10.1007/978-3-642-01965-4 6 Joseph R. Masiero T. Grav A. K. Mainzer C. R. Nugent J. M. Bauer R. Stevenson S. Sonnett August 2014 Main-belt Asteroids with WISE/NEOWISE: Near-infrared Albedos http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2014ApJ...791..121M The Astrophysical Journal 791 2 11 2014ApJ...791..121M 10.1088/0004-637X/791/2/121 1406.6645 29 October 2016 1796 29 October 2016 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 free (online, AcuA catalog p. 153) E. F. Tedesco P. V. Noah M. Noah S. D. Price October 2004 IRAS Minor Planet Survey V6.0 https://sbnarchive.psi.edu/pds3/iras/IRAS_A_FPA_3_RDR_IMPS_V6_0/data/diamalb.tab NASA Planetary Data System – IRAS-A-FPA-3-RDR-IMPS-V6.0 2004PDSS...12.....T 17 October 2019 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 6 V. Alí-Lagoa J. de León J. Licandro M. Delbó H. Campins N. Pinilla-Alonso M. S. Kelley June 2013 Physical properties of B-type asteroids from WISE data http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2013A&A...554A..71A Astronomy and Astrophysics 554 16 2013A&A...554A..71A 10.1051/0004-6361/201220680 1303.5487 29 October 2016 6 V. Alí-Lagoa J. Licandro R. Gil-Hutton Cañ M. ada-Assandri M. Delbo' J. de León H. Campins N. Pinilla-Alonso M. S. P. Kelley J. Hanus June 2016 Differences between the Pallas collisional family and similarly sized B-type asteroids http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2016A&A...591A..14A Astronomy and Astrophysics 591 11 2016A&A...591A..14A 10.1051/0004-6361/201527660 10 August 2016 free 11336/63614 free Warner, Brian D. March 2004 Rotation rates for asteroids 875, 926, 1679, 1796, 3915, 4209, and 34817 http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2004MPBu...31...19W The Minor Planet Bulletin 31 1 19–22 1052-8091 2004MPBu...31...19W 17 November 2015 Chiorny, V. G. Shevchenko, V. G. Krugly, Yu. N. Velichko, F. P. Gaftonyuk, N. M. May 2007 Photometry of asteroids: Lightcurves of 24 asteroids obtained in 1993 2005 http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2007P&SS...55..986C Planetary and Space Science 55 7–8 986–997 2007P&SS...55..986C 10.1016/j.pss.2007.01.001 17 November 2015 Warner, Brian D. April 2011 Upon Further Review: VI. An Examination of Previous Lightcurve Analysis from the Palmer Divide Observatory http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2011MPBu...38...96W The Minor Planet Bulletin 38 2 96–101 1052-8091 2011MPBu...38...96W 17 November 2015 Oey, Julian January 2016 Lightcurve Analysis of Asteroids from Blue Mountains Observatory in 2014 http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2016MPBu...43...45O The Minor Planet Bulletin 43 1 45–51 1052-8091 2016MPBu...43...45O 29 October 2016 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 http://adsabs.harvard.edu/cgi-bin/bib_query?bibcode=2015Icar..261...34V Icarus 261 34–47 2015Icar..261...34V 10.1016/j.icarus.2015.08.007 1506.00762 29 October 2016 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 Asteroids and comets rotation curves, CdR https://web.archive.org/web/20160729213840/http://obswww.unige.ch/~behrend/page_cou.html 29 July 2016 – Observatoire de Genève, Raoul Behrend Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center 1796 1795 Woltjer 1796 1797 Schaumasse 001796 Category:Discoveries by Nikolai Chernykh Category:Named minor planets 001796 001796 19660516