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[1]
Discovered byATLAS
Discovery date1 March 2023
Orbital characteristics[2]
Epoch25 May 2023
Observation arc214 days
Earliest precovery date25 December 2022
Aphelion37.660 AU
Perihelion1.027 AU
Semi-major axis19.343 AU
Eccentricity0.947
Orbital period85.07 years
Inclination38.313°
164.57°
Argument of
periapsis		105.89°
Last perihelion1 July 2023
Earth MOID0.365 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.[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 Ursa Minor. 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]

The comet seems to be in a 2:1 orbital resonance with Neptune, with the comet completing two orbits for every orbit Neptune does.[7]

  1. ^ a b "MPEC 2023-E59 : COMET C/2023 E1 (ATLAS)". www.minorplanetcenter.net. Retrieved 29 July 2023.
  2. ^ "Small-Body Database Lookup:C/2023 E1 (ATLAS)". ssd.jpl.nasa.gov. Retrieved 29 July 2023.
  3. ^ Green, Daniel. "Electronic Telegram No. 5233: COMET C/2023 E1 (ATLAS)". Central Bureau Electronic Telegrams. Retrieved 29 July 2023.
  4. ^ Tingley, Brett (29 June 2023). "How to see comet E1 ATLAS high in the night sky in July near the Little Dipper". Space.com. Retrieved 29 July 2023.
  5. ^ "Comet C/2023 E1 (ATLAS)". COBS - Comet OBServation database. Retrieved 29 July 2023.
  6. ^ "APOD: 2023 July 14 - Comet C/2023 E1 ATLAS near Perihelion". apod.nasa.gov. Retrieved 29 July 2023.
  7. ^ a b Dickinson, David (27 June 2023). "Follow Comet E1 Atlas Through the July Sky". Universe Today. Retrieved 29 July 2023.