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168P/Hergenrother

Periodic comet with 7 year orbit

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] (Not recovered) 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 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]

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 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.

References

^ Math: ${\displaystyle ({\sqrt[{5}]{100}})^{15.2-8}\approx 758}$

External links

• Orbital simulation from JPL (Java) / Horizons Ephemeris
• 168P on Seiichi Yoshida's comet list
• Elements and Ephemeris for 168P/Hergenrother – Minor Planet Center
• 168P at Kronk's Cometography
• 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-metre (140 in) on 30 Oct 2012
• Scientists Monitor Comet Breakup (168P-Hergenrother was imaged by the NOAO/Gemini telescope Nov. 2, 2012)
• Temporal Correlation Between Outbursts and Fragmentation Events of Comet 168P/Hergenrother (arXiv:1409.7641 : 26 Sep 2014)