168P/Hergenrother

Periodic comet April 2025 168P/Hergenrother 168p-hergenrother.jpg 168P/Hergenrother during its 2012 outburst as imaged from the Mount Lemmon Observatory IAUC_7057 Carl W. Hergenrother Catalina Sky Survey 22 November 1998 P/1998 W2, P/2005 N2 jpl1 MPC 25 February 2023 (JD 2460000.5) 21.12 yearsobs_arc 21 November 1998 3,633 1.357 AU 5.817 AU 3.587 AU 6.794 years 0.62169 21.615° 355.43° 15.041° 188.01° 2.663 0.420 AU 0.001 AU jpl1 0.91 km miParadowski_2020 7.0 15.2 8.0(2012 apparition) 18 May 2026 25 April 2033Horizons2033 168P/Hergenrother is a periodic comet in the Solar System. The comet, originally named P/1998 W2, returned in 2005 and got the temporary name P/2005 N2.IAUC_8560 It was last observed in January 2020MPC and may have continued fragmenting after the 2012 outburst. It was last observed in 2020MPC and came to perihelion in May 2026. It will return to perihelion in 2033.Horizons2033 Observational history Discovery On 22 November 1998, Carl W. Hergenrother spotted a new comet from CCD images taken by Timothy B. Spahr a day earlier with the Catalina Sky Survey's 0.41 m in telescope.cometography Preliminary orbital calculations by Brian G. Marsden reveal that the comet has a periodic orbit of 6.78 years.IAUC_7057 At the time, the comet was a 17th-magnitude object within the constellation Ursa Minor.Reported initial position upon discovery was: α 21 15 03.67, δ –14 37 45IAUC_7057 Between 2000 and 2002, Kazuo Kinoshita and Shuichi Nakano independently used the comet's positions during its 1998 apparition to predict its next perihelion date, which is around 2 November 2005.cometography It was successfully recovered by Australian astronomer, David Herald, on 6 November 2005.IAUC_8560 2012 outburst The comet came to perihelion on 1 October 2012,NK1778 and was expected to reach about apparent magnitude 15.2, but due to an outburst the comet reached apparent magnitude 8.Yoshida_2012 As a result of the outburst of gas and dust, the comet was briefly more than 500 times brighter than it would have been without the outburst.Apparent magnitude: On 19 October, images by the Virtual Telescope Project showed a dust cloud trailing the nucleus.Masi_2012 Images by the 2 m in Faulkes Telescope North on 26 October,jpl2 confirm a fragmentation event.Sostero_2012 The secondary fragment was about magnitude 17. Further observations by the 8.1 m in Gemini telescope show that the comet fragmented into at least four parts in six fragmentation events.jpl2 Plait_2012 Sekanina_2014 2019 apparition 168P came to perihelion on 5 August 2019,MPC when it was 76 degrees from the Sun. It then made a closest approach to Earth on 6 November 2019, when it was 1 AU e6km unit from Earth with a solar elongation of about 110 degrees. It was not recovered until 3 January 2020, when it was 141 degrees from the Sun, but only two observations on a single night were reported. Physical characteristics Observations conducted by the Spitzer Space Telescope between 2006 and 2007 showed that Hergenrother's nucleus was originally about 0.96 km mi in diameter before it fragmented on its 2012 outburst.Fernandez_2013 This was later revised to 0.91 km mi upon reanalysis of data in 2020.Paradowski_2020 Notes "obs_arc" Observation arc from the Minor Planet Center database covering dates from 21 November 1998 until 3 January 2020. References G. W. Kronk 168P/Hergenrother https://cometography.com/pcomets/168p.html Cometography.com 2025-04-01 C. W. Hergenrother B. G. Marsden Comet C/1998 W2 (Hergenrother) http://www.cbat.eps.harvard.edu/iauc/07000/07057.html IAU Circular 1998-11-23 7057 1 1998IAUC.7057....1H Y. R. Fernández M. S. Kelley P. L. Lamy I. Toth O. Groussin C. M. Lisse M. F. A’Hearn J. M. Bauer H. Campins A. Fitzsimmons J. Licandro S. C. Lowry K. J. Meech J. Pittichová W. T. Reach C. Snodgrass H. A. Weaver 5 Thermal Properties, Sizes, and Size Distribution of Jupiter-family Cometary Nuclei Icarus 2013 226 1 1138–1170 2013Icar..226.1138F 1307.6191 10.1016/j.icarus.2013.07.021 D. Herald D. W. Green Comet P/2005 N2 (Hergenrother) http://www.cbat.eps.harvard.edu/iauc/08500/08560.html IAU Circular 8560 1 2005-07-05 168P/Hergenrother – JPL Small-Body Database Lookup https://ssd.jpl.nasa.gov/tools/sbdb_lookup.html#/?sstr=168P ssd.jpl.nasa.gov Jet Propulsion Laboratory 2025-04-01 D. C. Agle Scientists Monitor Comet Break-up jpl.nasa.gov Jet Propulsion Laboratory https://www.jpl.nasa.gov/news/scientists-monitor-comet-breakup/ 2012-11-02 2025-04-01 2012-349 G. Masi Comet 168P/Hergenrother: hi-res images http://www.virtualtelescope.eu/2012/10/22/comet-168phergenrother-hi-res-images-19-oct-2012/ Virtual Telescope Project 2012-10-19 2016-10-18 168P/Hergenrother Orbit http://www.minorplanetcenter.net/db_search/show_object?object_id=168P Minor Planet Center 2014-06-20 S. Nakano 168P/Hergenrother (NK 1778) OAA Computing and Minor Planet Sections http://www.oaa.gr.jp/~oaacs/nk/nk1778.htm 2009-04-23 2012-02-20 M. L. Paradowski A New Method of Determining Brightness and Size of Cometary Nuclei https://academic.oup.com/mnras/article-pdf/492/3/4175/32217737/stz3597.pdf Monthly Notices of the Royal Astronomical Society 2020 492 3 4175–4188 2020MNRAS.492.4175P 10.1093/mnras/stz3597 free P. Plait Breaking up is easy to do. If you're a comet http://blogs.discovermagazine.com/badastronomy/2012/11/05/breaking-up-is-easy-to-do-if-youre-a-comet/ Bad Astronomy 2012-11-05 2012-11-06 2012-11-08 https://web.archive.org/web/20121108035433/http://blogs.discovermagazine.com/badastronomy/2012/11/05/breaking-up-is-easy-to-do-if-youre-a-comet/ dead Z. Sekanina Temporal Correlation Between Outbursts and Fragmentation Events of Comet 168P/Hergenrother 2014 1409.7641 astro-ph.EP G. Sostero N. Howes E. Guido Splitting event in comet 168P/Hergenrother http://remanzacco.blogspot.it/2012/10/splitting-event-in-comet.html Remanzacco Observatory in Italy – Comets & Neo 2012-10-26 2012-10-28 S. Yoshida 168P/Hergenrother (2012) http://www.aerith.net/comet/catalog/0168P/2012.html www.aerith.net 2012-02-21 2012-02-25 Horizons Batch for 168P/Hergenrother (90001117) on 2033-Apr-25 JPL Horizons Perihelion occurs when rdot flips from negative to positive https://ssd.jpl.nasa.gov/api/horizons.api?format=text&COMMAND=%27DES%3D168P%3BCAP%27&START_TIME=%272033-Apr-25%27&STOP_TIME=%272033-Apr-26%27&STEP_SIZE=%272%20hours%27&QUANTITIES=%2719%27 2026-10-05 (Soln.date: 2025-Nov-21) External links 1000242 168P 168P/Hergenrother at the Minor Planet Center database 168P/Hergenrother at Seiichi Yoshida's website 168P/Hergenrother at Gideon van Buitenen's website Comet 168P Hergenrother in outburst (Google+ chat archive Oct 12, 2012) Comet Hergenrother in Outburst (Carl Hergenrother : 20 Oct 2012) Comet 168P and fragment as seen by Kitt Peak WIYN 3.5 m in on 30 Oct 2012 167P/CINEOS 169P/NEAT Category:Periodic comets 168P 0168 168P 168P 168P **