None available.

C/2017 O1 (ASASSN) at perigee

Dominic Ford, Editor
From the Comets feed

Please wait
Loading 0/4
Click and drag to rotate
Mouse wheel to zoom in/out
Touch with mouse to dismiss
The sky at

Comet C/2017 O1 (ASASSN) will make its closest approach to the Earth, at a distance of 0.71 AU.

From Fairfield the 2017 apparition of C/2017 O1 (ASASSN) 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.
14 Oct 2017 – C/2017 O1 (ASASSN) at perihelion
16 Oct 2017 – C/2017 O1 (ASASSN) reaches its brightest
17 Oct 2017 – C/2017 O1 (ASASSN) at perigee
26 Sep 2017TaurusVisible from 23:03 until 05:41
Highest at 04:53, 80° above S horizon
28 Sep 2017PerseusVisible from 22:50 until 05:43
Highest at 04:48, 82° above S horizon
30 Sep 2017PerseusVisible from 22:37 until 05:45
Highest at 04:43, 84° above S horizon
02 Oct 2017PerseusVisible from 22:24 until 05:47
Highest at 04:38, 86° above S horizon
04 Oct 2017PerseusVisible from 22:11 until 05:50
Highest at 04:33, 89° above S horizon
06 Oct 2017PerseusVisible from 21:57 until 05:52
Highest at 04:27, 89° above N horizon
08 Oct 2017PerseusVisible from 21:42 until 05:54
Highest at 04:22, 87° above N horizon
10 Oct 2017PerseusVisible from 21:26 until 05:56
Highest at 04:17, 84° above N horizon
12 Oct 2017PerseusVisible from 21:10 until 05:58
Highest at 04:11, 82° above N horizon
14 Oct 2017PerseusVisible from 20:53 until 06:00
Highest at 04:06, 80° above N horizon
16 Oct 2017CamelopardalisVisible from 20:35 until 06:02
Highest at 04:00, 77° above N horizon
18 Oct 2017CamelopardalisVisible from 20:15 until 06:04
Highest at 03:55, 75° above N horizon
20 Oct 2017CamelopardalisVisible from 19:54 until 06:06
Highest at 03:49, 73° above N horizon
22 Oct 2017CamelopardalisVisible from 19:08 until 06:09
Highest at 03:43, 71° above N horizon
24 Oct 2017CamelopardalisVisible from 19:06 until 06:11
Highest at 03:37, 69° above N horizon
26 Oct 2017CamelopardalisVisible from 19:03 until 06:13
Highest at 03:31, 67° above N horizon
28 Oct 2017CamelopardalisVisible from 19:01 until 06:15
Highest at 03:24, 65° above N horizon
30 Oct 2017CamelopardalisVisible from 18:58 until 06:17
Highest at 03:18, 63° above N horizon
01 Nov 2017CamelopardalisVisible from 18:56 until 06:19
Highest at 03:11, 61° above N horizon
03 Nov 2017CamelopardalisVisible from 18:54 until 06:21
Highest at 03:04, 59° above N horizon
05 Nov 2017CamelopardalisVisible from 17:52 until 05:23
Highest at 01:56, 57° above N horizon

A more detailed table of C/2017 O1 (ASASSN)'s position on each night is available here. A diagram of the orbit of C/2017 O1 (ASASSN) is available here.

Finder chart

The chart below shows the path of C/2017 O1 (ASASSN) 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 C/2017 O1 (ASASSN) is currently available.

The comet's position at perihelion will be:

Object Right Ascension Declination Constellation Magnitude
Comet C/2017 O1 (ASASSN) 04h47m20s +54°14' Camelopardalis 8.8

The coordinates are given in J2000.0.

The sky on 17 October 2017
Twilight ends
Twilight begins

27-day old moon
Waning Crescent


27 days old

Rise Culm. Set
Mercury 07:39 13:01 18:24
Venus 05:22 11:25 17:27
Moon 04:52 11:07 17:22
Mars 04:46 10:58 17:09
Jupiter 07:42 13:06 18:30
Saturn 11:58 16:38 21:18
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 18 Jul 2020.

Image credit

None available.




Color scheme