Comet 398P/Boattini passes perihelion

Dominic Ford, Editor
From the Comets feed


Comet 398P/Boattini will make its closest approach to the Sun on 26 December, at a distance of 1.31 AU.

From South El Monte on the day of perihelion it will be visible between 18:05 and 02:09. It will become accessible at around 18:05, when it rises to an altitude of 21° above your eastern horizon. It will reach its highest point in the sky at 22:07, 52° above your southern horizon. It will become inaccessible at around 02:09 when it sinks below 21° above your western horizon.

The events that comprise the 2020–2021 apparition of 398P/Boattini are as follows:

Date Event
26 Dec 2020Comet 398P/Boattini passes perihelion

The table below lists the times when 398P/Boattini will be visible from South El Monte day-by-day through its apparition:

Date Constellation Comet visibility
05 Dec 2020EridanusVisible from 19:43 until 02:48
Highest at 23:16, 44° above S horizon
07 Dec 2020EridanusVisible from 19:34 until 02:43
Highest at 23:09, 45° above S horizon
09 Dec 2020EridanusVisible from 19:25 until 02:38
Highest at 23:02, 45° above S horizon
11 Dec 2020EridanusVisible from 19:16 until 02:34
Highest at 22:55, 46° above S horizon
13 Dec 2020EridanusVisible from 19:07 until 02:29
Highest at 22:48, 47° above S horizon
15 Dec 2020EridanusVisible from 18:57 until 02:26
Highest at 22:41, 47° above S horizon
17 Dec 2020EridanusVisible from 18:48 until 02:22
Highest at 22:35, 48° above S horizon
19 Dec 2020EridanusVisible from 18:38 until 02:19
Highest at 22:28, 49° above S horizon
21 Dec 2020EridanusVisible from 18:28 until 02:16
Highest at 22:22, 50° above S horizon
23 Dec 2020EridanusVisible from 18:19 until 02:13
Highest at 22:16, 51° above S horizon
25 Dec 2020EridanusVisible from 18:09 until 02:10
Highest at 22:10, 52° above S horizon
27 Dec 2020EridanusVisible from 18:00 until 02:08
Highest at 22:04, 53° above S horizon
29 Dec 2020EridanusVisible from 17:55 until 02:06
Highest at 21:58, 54° above S horizon
31 Dec 2020EridanusVisible from 17:57 until 02:04
Highest at 21:53, 55° above S horizon
02 Jan 2021OrionVisible from 17:58 until 02:02
Highest at 21:47, 57° above S horizon
04 Jan 2021OrionVisible from 18:00 until 02:00
Highest at 21:42, 58° above S horizon
06 Jan 2021OrionVisible from 18:01 until 01:59
Highest at 21:37, 59° above S horizon
08 Jan 2021OrionVisible from 18:03 until 01:57
Highest at 21:32, 60° above S horizon
10 Jan 2021OrionVisible from 18:04 until 01:56
Highest at 21:27, 62° above S horizon
12 Jan 2021OrionVisible from 18:06 until 01:55
Highest at 21:22, 63° above S horizon
14 Jan 2021OrionVisible from 18:08 until 01:53
Highest at 21:18, 64° 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.

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.

No estimate for the brightness of comet 398P/Boattini is currently available.

The comet's position at perihelion will be:

Object Right Ascension Declination Constellation Magnitude
Comet 398P/Boattini 04h39m50s 3°17'S Eridanus 11.9

The coordinates are given in J2000.0.

The sky on 26 Dec 2020

The sky on 26 December 2020
Sunrise
06:54
Sunset
16:49
Twilight ends
18:19
Twilight begins
05:24


Waxing Gibbous

91%

12 days old

Planets
Rise Culm. Set
Mercury 07:19 12:09 16:58
Venus 05:17 10:18 15:19
Moon 14:31 21:31 04:37
Mars 12:27 18:59 01:30
Jupiter 08:38 13:43 18:48
Saturn 08:36 13:41 18:45
All times shown in PST.

Source

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 Dec 2025.

Image credit

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

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