Objects in your sky: Comets
Below is a list of the brightest few comets that are visible at present.
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Comet name | Mag | Constellation | Separation from Sun |
Trend |
Absolute magnitude last updated |
Comet name | Mag | Constellation | Separation from Sun |
Trend |
Absolute magnitude last updated |
C/2022 E3 (ZTF) | 5.9 | Auriga | 121° | Fading (peak at mag 5.4 on 1 Feb 2023) | 3 Jan 2023 |
C/2017 K2 (PANSTARRS) | 8.8 | Tucana | 56° | Fading (peak at mag 8.7 on 26 Jan 2023) | 3 Jan 2023 |
96P/Machholz | 9.1 | Aquila | 7° | Fading (peak at mag 4.0 on 31 Jan 2023) | 24 Dec 2016 |
C/2022 A2 (PANSTARRS) | 9.5 | Cygnus | 76° | Fading (peak at mag 9.4 on 30 Jan 2023) | 3 Jan 2023 |
C/2020 V2 (ZTF) | 9.9 | Perseus | 92° | Fading (peak at mag 9.6 on 3 Sep 2023) | 3 Jan 2023 |
81P/Wild | 10.6 | Scorpius | 72° | Fading (peak at mag 10.4 on 16 Jan 2023) | 4 Dec 2018 |
118P/Shoemaker-Levy | 11.0 | Cancer | 172° | Fading (peak at mag 10.7 on 7 Jan 2023) | 4 Dec 2018 |
C/2019 U5 (PANSTARRS) | 12.3 | Virgo | 110° | Brightening (peak at mag 11.9 on 24 Mar 2023) | 3 Jan 2023 |
237P/LINEAR | 12.8 | Ophiuchus | 58° | Brightening (peak at mag 10.5 on 23 Jun 2023) | 1 Dec 2016 |
C/2020 K1 (PANSTARRS) | 12.8 | Sagittarius | 30° | Brightening (peak at mag 11.5 on 5 Jun 2023) | 27 Sep 2022 |
C/2022 U2 (ATLAS) | 12.8 | Auriga | 119° | Fading (peak at mag 12.4 on 24 Jan 2023) | 3 Jan 2023 |
204P/LINEAR-NEAT | 12.8 | Leo | 162° | Fading (peak at mag 12.8 on 19 Jan 2023) | 29 Feb 2012 |
C/2019 L3 (ATLAS) | 13.0 | Antlia | 127° | Fading | 3 Jan 2023 |
C/2019 T4 (ATLAS) | 13.1 | Serpens Caput | 83° | Brightening (peak at mag 13.0 on 9 Mar 2023) | 3 Jan 2023 |
C/2022 P1 (NEOWISE) | 13.5 | Sagittarius | 29° | Fading | 3 Jan 2023 |
116P/Wild | 13.7 | Sagittarius | 40° | Fading | 4 Dec 2018 |
77P/Longmore | 13.7 | Libra | 95° | Brightening (peak at mag 12.7 on 22 Apr 2023) | 4 Dec 2018 |
C/2021 Y1 (ATLAS) | 14.3 | Eridanus | 89° | Fading (peak at mag 14.2 on 5 Jan 2023) | 3 Jan 2023 |
C/2021 X1 (Maury-Attard) | 14.4 | Eridanus | 83° | Fading (peak at mag 13.6 on 7 Sep 2023) | 3 Jan 2023 |
C/2020 R7 (ATLAS) | 14.9 | Ophiuchus | 44° | Brightening (peak at mag 14.7 on 11 Apr 2023) | 1 Aug 2022 |
110P/Hartley | 15.0 | Hydra | 95° | Brightening (peak at mag 14.8 on 27 Mar 2023) | 29 Feb 2012 |
94P/Russell | 15.1 | Cancer | 167° | Brightening (peak at mag 15.1 on 14 Feb 2023) | 4 Dec 2018 |
51P/Harrington | 15.3 | Pisces | 73° | Fading | 29 Feb 2012 |
C/2021 E3 (ZTF) | 15.3 | Canis Major | 124° | Fading | 3 Jul 2022 |
P/2014 W1 (PANSTARRS) | 15.6 | Aquarius | 13° | Brightening | 16 Apr 2015 |
The position of each comet is calculated from orbital elements published by the Minor Planet Center (MPC).
The brightnesses of comets are estimated from magnitude parameters published by the BAA Comet Section, where these are available. These are computed from the observations they receive from amateur astronomers.
Comets are intrinsically highly unpredictable objects, since their brightness depends on the scattering of sunlight from dust particles in the comet's coma and tail. This dust is continually streaming away from the comet's nucleus, and its density at any particular time is governed by the rate of sublimation of the ice in the comet's nucleus, as it is heated by the Sun's rays. It also depends on the amount of dust that is mixed in with that ice. This is very difficult to predict in advance, and can be highly variable even between successive apparitions of the same comet.
In consequence, while the future positions of comets are usually known with a high degree of confidence, their future brightnesses are not. For most comets, we do not publish any magnitude estimates at all. For the few comets where we do make estimates, we generally prefer the BAA's magnitude parameters to those published by the Minor Planet Center, since they are typically updated more often.