Comet C/2020 R4 (ATLAS) will make its closest approach to the Earth, at a distance of 0.46 AU.
|02 Mar 2021||– C/2020 R4 (ATLAS) at perihelion|
|12 Mar 2021||– C/2020 R4 (ATLAS) reaches its brightest|
|23 Apr 2021||– C/2020 R4 (ATLAS) at perigee|
|02 Apr 2021||Aquila||Visible from 03:54 until 05:49|
Highest at 05:49, 39° above SE horizon
|04 Apr 2021||Aquila||Visible from 03:33 until 05:45|
Highest at 05:45, 42° above SE horizon
|06 Apr 2021||Aquila||Visible from 03:10 until 05:42|
Highest at 05:42, 45° above SE horizon
|08 Apr 2021||Aquila||Visible from 02:45 until 05:38|
Highest at 05:38, 49° above SE horizon
|10 Apr 2021||Aquila||Visible from 02:16 until 05:35|
Highest at 05:35, 53° above SE horizon
|12 Apr 2021||Aquila||Visible from 01:45 until 05:32|
Highest at 05:32, 58° above SE horizon
|14 Apr 2021||Hercules||Visible from 01:09 until 05:28|
Highest at 05:28, 63° above S horizon
|16 Apr 2021||Hercules||Visible from 00:28 until 05:25|
Highest at 05:25, 67° above S horizon
|18 Apr 2021||Hercules||Visible from 23:40 until 05:22|
Highest at 05:02, 71° above S horizon
|20 Apr 2021||Hercules||Visible from 22:50 until 05:19|
Highest at 04:23, 75° above S horizon
|22 Apr 2021||Hercules||Visible from 21:58 until 05:15|
Highest at 03:40, 78° above S horizon
|24 Apr 2021||Corona Borealis||Visible from 21:05 until 05:12|
Highest at 02:53, 81° above S horizon
|26 Apr 2021||Bootes||Visible from 21:07 until 05:09|
Highest at 02:06, 83° above S horizon
|28 Apr 2021||Bootes||Visible from 21:10 until 05:06|
Highest at 01:20, 84° above S horizon
|30 Apr 2021||Canes Venatici||Visible from 21:12 until 05:03|
Highest at 00:38, 84° above S horizon
|02 May 2021||Canes Venatici||Visible from 21:15 until 05:00|
Highest at 23:56, 84° above S horizon
|04 May 2021||Canes Venatici||Visible from 21:17 until 04:57|
Highest at 23:23, 83° above S horizon
|06 May 2021||Coma Berenices||Visible from 21:20 until 04:41|
Highest at 22:53, 82° above S horizon
|08 May 2021||Coma Berenices||Visible from 21:22 until 04:12|
Highest at 22:28, 81° above S horizon
|10 May 2021||Coma Berenices||Visible from 21:25 until 03:47|
Highest at 22:05, 80° above S horizon
|12 May 2021||Ursa Major||Visible from 21:27 until 03:24|
Highest at 21:45, 79° above S horizon
The chart below shows the path of C/2020 R4 (ATLAS) over the course of its apparition, as calculated from the orbital elements published by the Minor Planet Center (MPC). It is available for download, either on dark background, in PNG, PDF or SVG formats, or on a light background, in PNG, PDF or SVG formats. It was produced using StarCharter.
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.
Based on the magnitude parameters published for this comet by the BAA Comet Section, we estimate that it may be around mag 7 at perigee. This estimate is based on observations that the BAA has received from amateur astronomers, assuming that its current level of activity will remain constant.
This comet is not expected to be visible to the naked eye, but might be visible through bird-watching binoculars.
The comet's position at perihelion will be:
|Comet C/2020 R4 (ATLAS)||16h21m50s||+27°49'||7.3|
The coordinates are given in J2000.0.
|The sky on 23 April 2021|
11 days old
All times shown in EDT.
This event was automatically generated on the basis of orbital elements published by the Minor Planet Center (MPC) , and is updated whenever new elements become available. It was last updated on 03 Feb 2021.
© Andy Roberts 1997. Pictured comet is C/1995 O1 Hale-Bopp.