112P/Urata–Niijima

Periodic comet with 6 year orbit August 2026 112P/Urata–Niijima 112P 2020-01-27 image ZTF-sso-447-zg-size-5.6arcmin.png Comet Urata–Niijima imaged from the Zwicky Transient Facility on 27 January 2020 IAUC_4267 Takeshi UrataTsuneo Niijima Ojima, Japan 30 October 1986 P/1986 UD, P/1986 WP 5 P/1986 TD 4 P/1993 U1ICQ1 1986 XVI, 1993 XII 1986o, 1993qICQ1 jpldata MPC 9 June 2026 (JD 2461200.5) 39.88 yearsobs_arc 4 October 1986 653 1.441 AU 5.601 AU 3.521 AU 0.59071 6.61 years 24.204° 31.794° 21.585° 344.36° 2.688 0.481 AU 0.316 AU Lamy_2009 0.90 0.05 km (V–R) 0.53 0.04Knight_2024 0.04 13.4 17.9 21 September 2026Horizons2026 3 April 2033Horizons2033 Comet Urata–Niijima, also known as 112P/Urata–Niijima, is a Jupiter-family comet with a 6.6-year orbit around the Sun. It was the only comet discovered by Japanese astronomers Takeshi Urata and Tsuneo Niijima. Observational history 1986 apparition The comet was first spotted by Urata and Niijima as a fast-moving asteroid-like object called 1986 UD, on 30 October 1986.IAUC_4267 At the time, it was a 16th-magnitude object within the constellation Aries.Reported initial position upon discovery was: α 2 03.2, δ 19 07Kronk Meyer Seargent 2017 234–237 Four days later, Tsutomu Seki would confirm the object's cometary nature after spotting a very faint, diffuse coma on 3 November 1986.IAUC_4269 Further observations by Miklós Lovas and orbital calculations by Brian G. Marsden determined the periodic nature of Urata–Niijima on 17 November 1986.IAUC_4270 Its brightness remained consistent at roughly 15–16 throughout the entire apparition.Hendrie_1987 The comet was last observed by Tom Gehrels on 27 March 1987.Kronk Meyer Seargent 2017 234–237 On August 1987, Shuichi Nakano would later link two asteroids, 1986 TD 4 and 1986 WP 5, as the same object as Comet Urata–Niijima.Kronk Meyer Seargent 2017 234–237 Subsequent apparitions The comet was recovered by James V. Scotti at the Kitt Peak Observatory on 20 October 1993.IAUC_5882 As with the previous apparition in 1986, the comet never went brighter than apparent magnitude 15, and it was an extremely faint 22nd-magnitude object when it was last seen in April 1994.Kronk Meyer Seargent 2017 805–806 Philippe L. Lamy and Harold A. Weaver used the Hubble Space Telescope to recover the comet on its next apparition on 4 March 2000.Lamy_2000 At the perihelion passage in late September 2026 the solar elongation will be 83 degrees with a declination of +34. The comet should brighten to about magnitude 15.5 placing it near the limit of smart telescopes. Physical characteristics The nucleus of the comet has an effective radius of 0.90 ± 0.05 km mi, assuming a geometric albedo of 0.04.Lamy_2009 During its 1983 apparition, emissions of CN, C3 and C2 were detected from Urata–Niijima's coma.IAUC_4284 Notes "obs_arc" Observation arc from the Minor Planet Center database covering dates from 4 October 1986 until 22 August 2026. References M. J. Hendrie Comet Section: Urata–Niijima 1986o (1986 UD) Journal of the British Astronomical Association 1987 97 2 67 1987JBAA...97...67H T. Urata T. Niijima B. G. Marsden 1986 UD http://www.cbat.eps.harvard.edu/iauc/04200/04267.html IAU Circular 1986-11-03 4267 2 1986IAUC.4267....2U T. Seki T. Urata T. Niijima K. Suzuki B. G. Marsden Comet Urata–Niijima (1986o) http://www.cbat.eps.harvard.edu/iauc/04200/04269.html IAU Circular 1986-11-05 4269 1 1986IAUC.4269....1S M. Lovas B. G. Marsden Periodic Comet Urata–Niijima (1986o) http://www.cbat.eps.harvard.edu/iauc/04200/04270.html IAU Circular 1986-11-17 4270 1 1986IAUC.4270....1L S. Wyckoff S. Tegler D. W. Green Spectroscopic Observations of Comets http://www.cbat.eps.harvard.edu/iauc/04200/04284.html IAU Circular 1986-12-17 4284 3 1986IAUC.4284....3W J. V. Scotti D. W. Green Periodic Comet Urata–Niijima (1993q) http://www.cbat.eps.harvard.edu/iauc/05800/05882.html IAU Circular 1993-10-21 5882 1 Comet Names and Designations http://www.icq.eps.harvard.edu/names1.html International Comet Quarterly 2026-08-29 112P/Urata–Niijima – JPL Small-Body Database Lookup https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=112P ssd.jpl.nasa.gov Jet Propulsion Laboratory 2023-11-21 M. M. Knight R. Kokotanekova N. H. Samarasinha K. J. Meech Comets III Physical and Surface Properties of Comet Nuclei from Remote Observations https://books.google.com/books?id=_dGz0AEACAAJ&pg=PA361 University of Arizona Press 2024 361–404 2304.09309 jj.21819446.18 P. L. Lamy I. Toth H. A. Weaver etal The nucleus of 13 short-period comets Bulletin of the American Astronomical Society 2000 32 1061 2000DPS....32.3604L P. L. Lamy I. Toth H. A. Weaver M. F. A'Hearn L. Jorda Properties of the nuclei and comae of 13 ecliptic comets from Hubble Space Telescope snapshot observations https://www.aanda.org/articles/aa/pdf/2009/47/aa11462-08.pdf Astronomy & Astrophysics 2009 508 2 1045–1056 2009A&A...508.1045L 125249770 10.1051/0004-6361/200811462 free 112P/Urata–Niijima Orbit http://www.minorplanetcenter.net/db_search/show_object?object_id=112P Minor Planet Center 2014-06-17 Horizons Batch for 112P/Urata–Niijima (90000986) on 2026-Sep-21 JPL Horizons Perihelion occurs when rdot flips from negative to positive https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27DES%3D112P%3BCAP%27&START_TIME=%272026-Sep-21%27&STOP_TIME=%272026-Sep-22%27&STEP_SIZE=%271%20hours%27&QUANTITIES=%2719%27 2023-07-08 https://web.archive.org/web/20230708130830/https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27DES%3D112P%3BCAP%27&START_TIME=%272026-Sep-18%27&STOP_TIME=%272026-Sep-24%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2719%27 live 2023-07-06 (JPL#35 Soln.date: 2021-Sep-20) Horizons Batch for 112P/Urata–Niijima (90000997) on 2033-Apr-03 JPL Horizons Perihelion occurs when rdot flips from negative to positive https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27DES%3D112P%3BCAP%27&START_TIME=%272033-Apr-03%27&STOP_TIME=%272033-Apr-04%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2719%27 2026-10-05 (JPL#K264/13 Soln.date: 2026-Oct-01) Bibliography Kronk Gary W. Meyer Maik Seargent David A. J. 2017 Cometography: A Catalog of Comets 6: 1983–1993 Cambridge University Press 978-0-521-87216-4 External links 1000113 112P 112P/Urata–Niijima at the Minor Planet Center database 112P/Urata–Niijima at Gary W. Kronk's Cometography 112P/Urata–Niijima at Kazuo Kinoshita's Comets 112P/Urata–Niijima at Seiichi Yoshida's website 112P/Urata–Niijima at Gideon van Buitenen's website 111P/Helin–Roman–Crockett 113P/Spitaler Category:Periodic comets 0112 0112 112P 112P 112P * *