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

48P/Johnson at perihelion

Dominic Ford, Editor
From the Comets feed

Objects: 48P/Johnson
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Comet 48P/Johnson will make its closest approach to the Sun, at a distance of 2.01 AU.

From Fairfield the 2018 apparition of 48P/Johnson 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.
13 Aug 2018 – 48P/Johnson at perihelion
23 Jul 2018AquariusVisible from 01:21 until 04:23
Highest at 03:32, 29° above S horizon
25 Jul 2018AquariusVisible from 01:17 until 04:25
Highest at 03:24, 29° above S horizon
27 Jul 2018AquariusVisible from 01:13 until 04:27
Highest at 03:17, 28° above S horizon
29 Jul 2018AquariusVisible from 01:09 until 04:30
Highest at 03:09, 28° above S horizon
31 Jul 2018AquariusVisible from 01:05 until 04:33
Highest at 03:01, 28° above S horizon
02 Aug 2018AquariusVisible from 01:02 until 04:35
Highest at 02:54, 27° above S horizon
04 Aug 2018AquariusVisible from 00:58 until 04:33
Highest at 02:46, 27° above S horizon
06 Aug 2018AquariusVisible from 00:55 until 04:20
Highest at 02:38, 26° above S horizon
08 Aug 2018AquariusVisible from 00:51 until 04:07
Highest at 02:29, 26° above S horizon
10 Aug 2018AquariusVisible from 00:48 until 03:54
Highest at 02:21, 26° above S horizon
12 Aug 2018AquariusVisible from 00:45 until 03:40
Highest at 02:13, 25° above S horizon
14 Aug 2018AquariusVisible from 00:43 until 03:26
Highest at 02:04, 25° above S horizon
16 Aug 2018AquariusVisible from 00:41 until 03:11
Highest at 01:56, 24° above S horizon
18 Aug 2018Piscis AustrinusVisible from 00:39 until 02:56
Highest at 01:47, 24° above S horizon
20 Aug 2018Piscis AustrinusVisible from 00:37 until 02:41
Highest at 01:39, 24° above S horizon
22 Aug 2018Piscis AustrinusVisible from 00:36 until 02:24
Highest at 01:30, 23° above S horizon
24 Aug 2018Piscis AustrinusVisible from 00:36 until 02:07
Highest at 01:22, 23° above S horizon
26 Aug 2018Piscis AustrinusVisible from 00:38 until 01:48
Highest at 01:13, 22° above S horizon
28 Aug 2018Piscis AustrinusVisible from 00:44 until 01:25
Highest at 01:04, 22° above S horizon
30 Aug 2018Piscis AustrinusNot observable
01 Sep 2018Piscis AustrinusNot observable

A more detailed table of 48P/Johnson's position on each night is available here. A diagram of the orbit of 48P/Johnson is available here.

At the moment of perihelion it will be visible between 00:43 and 03:35. It will become accessible around 00:43, when it rises to an altitude of 21° above your southern horizon. It will reach its highest point in the sky at 02:09, 25° above your southern horizon. It will become inaccessible around 03:35 when it sinks below 22° above your southern horizon.

Finder chart

The chart below shows the path of 48P/Johnson 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 48P/Johnson is currently available.

The comet's position at perihelion will be:

Object Right Ascension Declination Constellation Magnitude
Comet 48P/Johnson 22h41m50s -23°51' Aquarius 11.6

The coordinates are given in J2000.0.

The sky on 13 August 2018
Twilight ends
Twilight begins

2-day old moon
Waxing Crescent


2 days old

Rise Culm. Set
Mercury 05:33 12:22 19:12
Venus 09:57 15:47 21:38
Moon 08:43 15:08 21:34
Mars 19:16 23:37 04:02
Jupiter 13:07 18:15 23:23
Saturn 16:58 21:36 02:18
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 06 Dec 2020.

Image credit

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






Color scheme