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.[4] The comet was last observed in February 2013,[1] and may have continued fragmenting after the 2012 outburst.

168P/Hergenrother during its 2012 outburst. By Mount Lemmon Observatory.
Discovered byCarl W. Hergenrother
Discovery dateNovember 22, 1998
P/1998 W2
P/2005 N2
Orbital characteristics A
EpochMarch 6, 2006
Aphelion5.839 AU
Perihelion1.426 AU
Semi-major axis3.632 AU
Orbital period6.923 a
Earth MOID0.4 AU (60 million km)
Last perihelionAugust 5, 2019[1][2]
(Not recovered)
October 1, 2012[3]
November 2, 2005
Next perihelion2026-May-18[1]

2012 outburstEdit

The comet came to perihelion on 1 October 2012,[3] and was expected to reach about apparent magnitude 15.2, but due to an outburst the comet reached apparent magnitude 8.[5] 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.[6] On 19 October 2012, images by the Virtual Telescope Project showed a dust cloud trailing the nucleus.[7] Images by the 2 m (79 in) Faulkes Telescope North on 26 October 2012 confirm a fragmentation event.[8] The secondary fragment was about magnitude 17. Further observations by the 8.1 m (320 in) Gemini telescope show that the comet fragmented into at least four parts.[9]


168P came to perihelion around August 5, 2019,[1] when it was expected to be 76 degrees from the Sun. 168P has not yet been recovered and may have disintegrated. During this perihelion passage 168P will make a closest approach to Earth in early November 2019 when it will be 1 AU (150 million km) from Earth with a solar elongation of about 110 degrees.


  1. ^ a b c d "168P/Hergenrother Orbit". Minor Planet Center. Retrieved 2014-06-20.
  2. ^ Syuichi Nakano (2012-07-17). "168P/Hergenrother (NK 2283)". OAA Computing and Minor Planet Sections. Retrieved 2012-10-13.
  3. ^ a b Syuichi Nakano (2009-04-23). "168P/Hergenrother (NK 1778)". OAA Computing and Minor Planet Sections. Retrieved 2012-02-20.
  4. ^ IAUC 8560: recovery of comet P/1998 W2
  5. ^ Seiichi Yoshida (2012-02-21). "168P/Hergenrother (2012)". Seiichi Yoshida's Comet Catalog. Retrieved 2012-02-25.
  6. ^ Math:  
  7. ^ Gianluca Masi (October 19, 2012). "Comet 168P/Hergenrother: hi-res images (19 Oct. 2012)". Virtual Telescope Project. Retrieved 2016-10-18.
  8. ^ Giovanni Sostero; Nick Howes; Ernesto Guido (October 26, 2012). "Splitting event in comet 168P/Hergenrother". Remanzacco Observatory in Italy – Comets & Neo. Retrieved 2012-10-28.
  9. ^ Phil Plait (2012-11-05). "Breaking up is easy to do. If you're a comet". Bad Astronomy. Retrieved 2012-11-05.

External linksEdit

Numbered comets
168P/Hergenrother Next