C/2023 E1 (ATLAS)

C/2023 E1 (ATLAS)
	The comet on 24 July 2023
Discovery
Discovered by	ATLAS
Discovery date	1 March 2023
Orbital characteristics
Epoch	25 May 2023
Observation arc	214 days
Earliest precovery date	25 December 2022
Aphelion	37.660 AU
Perihelion	1.027 AU
Semi-major axis	19.343 AU
Eccentricity	0.947
Orbital period	85.07 years
Inclination	38.313°
Longitude of; ascending node	164.57°
Argument of; periapsis	105.89°
Last perihelion	1 July 2023
Earth MOID	0.365 AU
Comet total; magnitude (M1)	16.1
Comet nuclear; magnitude (M2)	18.3

C/2023 E1 (ATLAS) is a periodic comet with an orbital period of 85 years. It fits the classical definition of a Halley-type comet with an orbital period of between 20 and 200 years. The comet was discovered on 1 March 2023 by ATLAS South Africa. Upon discovery, the comet had an apparent magnitude of about 19 and had a very condensed coma. The comet was subsequently precovered in images obtained by other observatories back on 25 December 2022.^[1]^[3]

The comet brightened in late June to a magnitude of +10, and became visible in small telescopes and binoculars. At that time it was located high in the northern skies, in the constellation of Little Dipper. It passed its perihelion on 1 July and reached an apparent magnitude between 8 and 9.^[4]^[5] The comet had a greenish coma and a faint narrow ion tail.^[6] On July 8 it passed 9 degrees from the north celestial pole. The closest approach to Earth was on 18 August, at a distance of 0.375 AU.^[7]