168P/Hergenrother

168P/Hergenrother during its 2012 outburst. By Mount Lemmon Observatory.
Discovery
Discovered by	Carl W. Hergenrother
Discovery date	November 22, 1998
Designations
Alternative designations	P/1998 W2 P/2005 N2
Orbital characteristics
Epoch	March 6, 2006
Aphelion	5.839 AU
Perihelion	1.426 AU
Semi-major axis	3.632 AU
Eccentricity	0.6075
Orbital period	6.923 a
Inclination	21.8934°
Last perihelion	August 5, 2019[1][2] October 1, 2012[3] November 2, 2005
Next perihelion	2026-May-18[1]
Earth MOID	0.4 AU (60 million km)

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 January 2020,^[1] and may have continued fragmenting after the 2012 outburst.

2012 outburst

The comet came to perihelion on October 1, 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 October 19, 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 October 26, 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]

2019

168P came to perihelion on August 5, 2019,^[1] when it was 76 degrees from the Sun. It then made a closest approach to Earth on 6 November 6, 2019, when it was 1 AU (150 million km) from Earth with a solar elongation of about 110 degrees. It was not recovered until January 3, 2020, when it was 141 degrees from the Sun, but only two observations on a single night were reported.