Comet C/2010 X1 (Elenin) reaches peak brightness

Dominic Ford, Editor
From the Comets feed


Comet C/2010 X1 (Elenin) is forecast to reach the brightest point in its 2011 apparition on 15 October. At that time, it will lie at a distance of 0.85 AU from the Sun, and at a distance of 0.20 AU from the Earth.

From Cambridge on 15 October it will be visible in the dawn sky, rising at 03:15 (EDT) – 3 hours and 40 minutes before the Sun – and reaching an altitude of 27° above the eastern horizon before fading from view as dawn breaks at around 05:48.

The events that comprise the 2011 apparition of C/2010 X1 (Elenin) are as follows:

Date Event
15 Sep 2011Comet C/2010 X1 (Elenin) passes perihelion
15 Oct 2011Comet C/2010 X1 (Elenin) reaches peak brightness
22 Oct 2011Comet C/2010 X1 (Elenin) passes perigee

The table below lists the times when C/2010 X1 (Elenin) will be visible from Cambridge day-by-day through its apparition:

Date Constellation Comet visibility
24 Sep 2011VirgoNot observable
26 Sep 2011VirgoNot observable
28 Sep 2011VirgoNot observable
30 Sep 2011VirgoNot observable
02 Oct 2011VirgoNot observable
04 Oct 2011VirgoNot observable
06 Oct 2011VirgoNot observable
08 Oct 2011VirgoNot observable
10 Oct 2011VirgoNot observable
12 Oct 2011VirgoNot observable
14 Oct 2011LeoVisible from 05:32 until 05:47
Highest at 05:47, 21° above E horizon
16 Oct 2011LeoVisible from 04:41 until 05:49
Highest at 05:49, 30° above E horizon
18 Oct 2011LeoVisible from 03:45 until 05:53
Highest at 05:53, 40° above E horizon
20 Oct 2011LeoVisible from 02:44 until 05:58
Highest at 05:58, 51° above E horizon
22 Oct 2011CancerVisible from 01:41 until 06:02
Highest at 06:02, 63° above SE horizon
24 Oct 2011CancerVisible from 00:38 until 06:04
Highest at 06:04, 73° above SE horizon
26 Oct 2011GeminiVisible from 23:39 until 06:06
Highest at 06:06, 80° above S horizon
28 Oct 2011GeminiVisible from 22:48 until 06:07
Highest at 05:21, 81° above S horizon
30 Oct 2011AurigaVisible from 22:04 until 06:07
Highest at 04:37, 81° above S horizon
01 Nov 2011AurigaVisible from 21:29 until 06:07
Highest at 03:57, 81° above S horizon
03 Nov 2011AurigaVisible from 21:00 until 06:09
Highest at 03:22, 80° above S horizon

A more detailed table of C/2010 X1 (Elenin)'s position on each night is available here. A diagram of the orbit of C/2010 X1 (Elenin) is available here.

Finder chart

The chart below shows the path of C/2010 X1 (Elenin) 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/2010 X1 (Elenin) is currently available.

The comet's position on 15 October 2011 will be:

Object Right Ascension Declination Constellation Magnitude
Comet C/2010 X1 (Elenin) 11h02m30s 14°12'N Leo 4.0

The coordinates are given in J2000.0.

The sky on 14 Mar 2025

The sky on 14 March 2025
Sunrise
06:55
Sunset
18:49
Twilight ends
20:23
Twilight begins
05:21


Waning Gibbous

98%

14 days old

Planets
Rise Culm. Set
Mercury 07:15 13:42 20:10
Venus 06:44 13:27 20:09
Moon 18:25 00:49 07:01
Mars 12:49 20:35 04:21
Jupiter 10:30 18:00 01:31
Saturn 07:02 12:47 18:32
All times shown in EDT.

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 23 Feb 2025.

Image credit

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

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