C/2023 E1 (ATLAS)

For other comets discovered by the Asteroid Terrestrial-impact Last Alert System, see Comet 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 found in images obtained by other observatories back on 25 December 2022.

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 Ursa Minor. It passed its perihelion on 1 July and reached an apparent magnitude between 8 and 9. The comet had a greenish coma and a faint narrow ion tail. 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.

The comet seems to be in a 2:1 orbital resonance with Neptune, with the comet completing two orbits for every orbit Neptune does.

External links

• C/2023 E1 at the JPL Small-Body Database