© Andy Roberts 1997. Pictured comet is C/1995 O1 Hale-Bopp.

398P/Boattini at perihelion

Dominic Ford, Editor
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Comet 398P/Boattini will make its closest approach to the Sun, at a distance of 1.30 AU.

From Fairfield the 2020–2021 apparition of 398P/Boattini will progress as follows:

Begin typing the name of a town near to you, and then select the town from the list of options which appear below.
27 Dec 2020 – 398P/Boattini at perihelion
06 Dec 2020EridanusVisible from 20:07 until 02:20
Highest at 23:13, 37° above S horizon
08 Dec 2020EridanusVisible from 19:58 until 02:16
Highest at 23:07, 38° above S horizon
10 Dec 2020EridanusVisible from 19:49 until 02:13
Highest at 23:01, 38° above S horizon
12 Dec 2020EridanusVisible from 19:39 until 02:11
Highest at 22:55, 39° above S horizon
14 Dec 2020EridanusVisible from 19:30 until 02:09
Highest at 22:49, 40° above S horizon
16 Dec 2020EridanusVisible from 19:16 until 02:03
Highest at 22:40, 41° above S horizon
18 Dec 2020EridanusVisible from 19:07 until 02:02
Highest at 22:34, 41° above S horizon
20 Dec 2020EridanusVisible from 18:57 until 02:02
Highest at 22:29, 42° above S horizon
22 Dec 2020EridanusVisible from 18:44 until 01:58
Highest at 22:21, 43° above S horizon
24 Dec 2020EridanusVisible from 18:35 until 01:58
Highest at 22:16, 44° above S horizon
26 Dec 2020EridanusVisible from 18:22 until 01:54
Highest at 22:08, 45° above S horizon
28 Dec 2020EridanusVisible from 18:13 until 01:55
Highest at 22:04, 47° above S horizon
30 Dec 2020EridanusVisible from 18:01 until 01:53
Highest at 21:57, 48° above S horizon
01 Jan 2021OrionVisible from 17:53 until 01:54
Highest at 21:54, 49° above S horizon
03 Jan 2021OrionVisible from 17:50 until 01:52
Highest at 21:47, 50° above S horizon
05 Jan 2021OrionVisible from 17:51 until 01:51
Highest at 21:40, 51° above S horizon
07 Jan 2021OrionVisible from 17:52 until 01:53
Highest at 21:38, 53° above S horizon
09 Jan 2021OrionVisible from 17:52 until 01:52
Highest at 21:32, 54° above S horizon
11 Jan 2021OrionVisible from 17:57 until 01:51
Highest at 21:27, 55° above S horizon
13 Jan 2021OrionVisible from 17:58 until 01:51
Highest at 21:22, 56° above S horizon
15 Jan 2021OrionVisible from 17:58 until 01:54
Highest at 21:21, 58° above S horizon

A more detailed table of 398P/Boattini's position on each night is available here. A diagram of the orbit of 398P/Boattini is available here.

At the moment of perihelion it will be visible between 18:18 and 01:53. It will become accessible around 18:18, when it rises to an altitude of 21° above your south-eastern horizon. It will reach its highest point in the sky at 22:05, 45° above your southern horizon. It will become inaccessible around 01:53 when it sinks below 22° above your south-western horizon.

Finder chart

The chart below shows the path of 398P/Boattini 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.

Comet brightnesses

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 12 at perihelion. This estimate is based on observations that the BAA has received from amateur astronomers, assuming that its current level of activity will remain constant.

You will probably require a telescope to see this comet. It is unlikely to be visible through bird-watching binoculars, and even less likely to be visible to the unaided eye.

The comet's position at perihelion will be:

Object Right Ascension Declination Constellation Magnitude
Comet 398P/Boattini 04h39m40s -03°09' Eridanus 11.8

The coordinates are given in J2000.0.

The sky on 27 December 2020
Twilight ends
Twilight begins

13-day old moon
Waxing Gibbous


13 days old

Rise Culm. Set
Mercury 07:43 12:11 16:38
Venus 05:38 10:21 15:03
Moon 14:40 22:16 04:56
Mars 12:17 18:57 01:37
Jupiter 08:56 13:44 18:32
Saturn 08:51 13:38 18:26
All times shown in EST.


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 15 Mar 2021.

Image credit

© Andy Roberts 1997. Pictured comet is C/1995 O1 Hale-Bopp.






Color scheme