P/2020 MK4 (PanSTARRS)

P/2020 MK₄ (PanSTARRS) is a Chiron-type comet or active centaur orbiting in the outer Solar System between Jupiter and Saturn.^[3] It was discovered on 24 June 2020, by the Pan-STARRS survey at Haleakala Observatory in Hawaii, United States.^[4]

P/2020 MK₄ (PanSTARRS)

Discovery
Discovered by	Pan-STARRS 1
Discovery site	Haleakala Obs.
Discovery date	24 June 2020
Designations
MPC designation	2020 MK4
Minor planet category	Chiron-type comet[1] centaur[2]
Orbital characteristics[1]
Epoch 17 December 2020 (JD 2459200.5)
Uncertainty parameter 4
Observation arc	857 days (2.348 yr)
Aphelion	6.25417 AU (0.935611 Tm)
Perihelion	6.0253 AU (901.37 Gm)
Semi-major axis	6.14521 AU (0.919310 Tm)
Eccentricity	0.01952
Orbital period (sidereal)	15.23 yr (5564.22 d)
Mean anomaly	138.7°
Mean motion	0° 3m 52.917s / day
Inclination	6.72263°
Longitude of ascending node	1.446°
Argument of perihelion	164.5°
Earth MOID	5.03147 AU (752.697 Gm)
Jupiter MOID	0.578149 AU (86.4899 Gm)
TJupiter	3.005
Physical characteristics
Absolute magnitude (H)	11.3[1]

Size

A lower limit for the absolute magnitude of the nucleus is H_g = 11.30±0.03 that, for an albedo in the range 0.1—0.04, gives an upper limit for its size in the interval 23–37 km.^[3]

Colors

The comet's color indices, (g′–r′) = 0.42±0.04 and (r′–i′) = 0.17±0.04, indicates the comet's nucleus has a neutral or gray color.^[3]

Activity

P/2020 MK₄ was discovered in outburst state and by late 2020, it had returned to its regular brightness.^[5][3] It was recovered by the Lowell Discovery Telescope at an extremely faint apparent magnitude of 24.5 in September 2022.^[6] It was officially recognized as a comet by the Minor Planet Center on 20 November 2022, in which it was given the periodic comet designation P/2020 MK₄.^[7][8]

Orbital evolution

Centaurs have short dynamical lives due to strong interactions with the giant planets.^[9] P/2020 MK₄ follows a very chaotic orbital evolution that may lead it to be ejected from the Solar System during the next 200,000 yr.^[3] Extensive numerical simulations indicate that P/2020 MK₄ may have experienced relatively close flybys with comet 29P/Schwassmann–Wachmann, in some cases with one of both objects were transient Jovian satellites; during these events, P/2020 MK₄ may have crossed the coma of comet 29P when in outburst.^[3]

See also

• List of centaurs (small Solar System bodies) § 2020 MK4