171P/Spahr

Jupiter-family comet August 2026 171P/Spahr 171P_2019-01-24_image_ZTF-sso-559-zr-fov-3.5arcmin.png Comet 171P/Spahr as seen from the Zwicky Transient Facility (ZTF) on 24 January 2019 IAUC_7052 Timothy B. Spahr 16 November 1998 P/1998 W1, P/2005 R3 jpldata MPC 21 November 2025 (JD 2461000.5) 13 November 1998 997 3.553 AU 1.764 AU 5.342 AU 0.5033 6.70 a 21.94° Paradowski_2022 1.25 km mi 640 90 kg/m3 11.6 16.8 25 September 2025 3 June 2032Horizons2032 171P/Spahr is a periodic comet in the Solar System. 171P/Spahr was recovered on 20–24 October 2011 at apparent magnitude 20.6 using the 2.0 m in on Faulkes Telescope South. 171P/Spahr is peaked at about magnitude 18 in 2012. During the 1999 passage, the comet brightened to about magnitude 13.5. At perihelion on January 13, 2019, when the comet was 1AU from Earth, the 3-sigma uncertainty in the comet's Earth distance was ±500 km. References T. B. Spahr D. W. Green Comet 1998 W1 http://www.cbat.eps.harvard.edu/iauc/07000/07052.html IAU Circular 1998-11-17 7052 1 1998IAUC.7052....1S 171P/Spahr – JPL Small-Body Database Lookup https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=171P ssd.jpl.nasa.gov Jet Propulsion Laboratory 2026-08-12 171P/Spahr Orbit http://www.minorplanetcenter.net/db_search/show_object?object_id=171P Minor Planet Center 2019-02-25 M. L. Paradowski A New Indirect Method of Determining Density of Cometary Nuclei https://acta.astrouw.edu.pl/Vol72/n2/pdf/pap_72_2_4.pdf Acta Astronomica 2022 72 2 141–159 2022AcA....72..141P 0001-5237 10.32023/0001-5237/72.2.4 free October 28, 2011 Recovery of comet 171P/Spahr Remanzacco Observatory in Italy – Comets & Neo Ernesto Guido Giovanni Sostero Giovanni Sostero Nick Howes Nick Howes Antoni Kasprzyk amp https://remanzacco.blogspot.com/2011/10/recovery-of-comet-171pspahr.html 2011-11-01 2011-10-30 171P/Spahr Seiichi Yoshida's Comet Catalog Seiichi Yoshida http://www.aerith.net/comet/catalog/0171P/index.html 2010-03-01 Gary W. Kronk Gary W. Kronk 2001–2005 171P/Spahr http://cometography.com/pcomets/171p.html 2012-02-27 dead https://web.archive.org/web/20010405095745/http://cometography.com/ 2001-04-05 Horizons Batch for 171P/Spahr (90001118) on 2032-Jun-03 JPL Horizons Perihelion occurs when rdot flips from negative to positive https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27DES%3D171P%3BCAP%27&START_TIME=%272032-Jun-03%27&STOP_TIME=%272032-Jun-04%27&STEP_SIZE=%273%20hours%27&QUANTITIES=%2719%27 2026-04-16 (JPL#K254/9 Soln.date: 2026-Mar-07) External links 1000239 171P 171P/Spahr at the Minor Planet Center database 171P/Spahr at Gary W. Kronk's Cometography 171P/Spahr at Seiichi Yoshida's website 170P/Christensen 172P/Yeung Category:Periodic comets 171P 0171 171P 171P 171P * *