104P/Kowal

104P/Kowal, also known as Kowal 2, is a periodic Jupiter-family comet discovered by Charles T. Kowal in 1979. The orbit was confirmed after new sightings in 1991 and 1998.[2]

104P/Kowal

Comet 104P/Kowal on 12 February 2022 by ZTF
Discovery
Discovered by	Charles T. Kowal
Discovery date	13 January 1979
Designations
Alternative designations	Kowal 2 1979 B1, 1991 X1
Orbital characteristics
Epoch	31 July 2016
Observation arc	4,685 days (12.83 yr)
Number of observations	133
Aphelion	5.347 AU
Perihelion	1.179 AU
Semi-major axis	3.263 AU
Eccentricity	0.6387
Orbital period	5.90 yr
Inclination	10.252°
Longitude of ascending node	235.421°
Argument of periapsis	200.674°
Last perihelion	11 Jan 2022[1][2] 28 March 2016 4 May 2010
Next perihelion	2027-Oct-12[3]
TJupiter	2.794
Earth MOID	0.2004 AU
Jupiter MOID	0.1687 AU
Physical characteristics
Dimensions	2 ± 1 km[4]
Comet total magnitude (M1)	10.5 mag

The comet was in a orbit with a perihelion distance of 1.50 AU and an orbital period of 6.38 AU until an approach to Jupiter on 15 January 1996 reduced both to 1.40 AU and 6.18 years respectively.[5] A further encounter with Jupiter on 4 July 2007 at a distance of 0.300 AU reduced the perihelion distance to 1.18 AU and the orbital period to 5.90 years. One more close approach to Jupiter on 30 May 2019 reduced the perihelion distance to 1.07 AU and orbital period to 5.74 years.[6]

In 2003, Gary Kronk and Brian Marsden noticed that an object observed by Leo Boethin in 1973 was actually 104P/Kowal. From Boethin's report, it was apparent that comet Kowal 2 had been in a short, major outburst to apparent magnitude 9.5 in 1973.[7]

During the 1997–98 apparition, the comet was brighter than expected, reaching an apparent magnitude of 13 in mid January.[5] The comet wasn't observed during the 2010 apparition.[2] During the 2022 apparition, it brightened to a magnitude of 9.2 according to Chris Wyatt.[8]