C/2019 E3 (ATLAS)

For other comets discovered by the Asteroid Terrestrial-impact Last Alert System, see Comet ATLAS.

Comet ATLAS, formally designated as C/2019 E3, is an Oort cloud comet with a very distant perihelion of 10.30 AU (1.541 billion km), the third known comet with a perihelion distance beyond 10 AU after 167P/CINEOS and C/2003 A2 (Gleason).^[4][6]

C/2019 E3 (ATLAS)

Discovery[1][2]
Discovered by	D. Young
Discovery site	ATLAS–MLO (T08)
Discovery date	5 March 2019
Designations
Alternative designations	CK19E030 A10ckQ4[3]
Orbital characteristics[4]
Epoch	17 May 2022 (JD 2459716.5)
Observation arc	4,667 days (12.78 years)
Earliest precovery date	19 March 2012
Number of observations	980
Perihelion	10.314 AU
Semi-major axis	Barycentric: ~32,600 AU
Eccentricity	1.00154
Inclination	84.298°
Longitude of ascending node	347.25°
Argument of periapsis	280.66°
Mean anomaly	–0.001°
Last perihelion	14 November 2023
TJupiter	0.417
Earth MOID	10.07 AU
Jupiter MOID	8.331 AU
Physical characteristics[4][5]
Mean diameter	~3.0 km (1.9 mi)
Comet total magnitude (M1)	6.4
Comet nuclear magnitude (M2)	7.8

Precovery observations of this comet all the way to 2016 (and later 2012)^[4] have revealed that the comet had produced some cometary activity more than 20 AU (3.0 billion km) from the Sun, making it the fourth known distant comet to produce such activity at large distances after C/2010 U3 (Boattini), C/2014 UN271 (Bernardinelli–Bernstein), and C/2017 K2 (PanSTARRS).^[5]