Comet C/2009 G1 (STEREO) passes perihelion

Dominic Ford, Editor
From the Comets feed


Comet C/2009 G1 (STEREO) will make its closest approach to the Sun on 18 April, at a distance of 1.14 AU.

From Cambridge on the day of perihelion it will not be observable – it will reach its highest point in the sky during daytime and will be no higher than 7° above the horizon at dawn.

The events that comprise the 2009 apparition of C/2009 G1 (STEREO) are as follows:

Date Event
18 Apr 2009Comet C/2009 G1 (STEREO) passes perihelion

The table below lists the times when C/2009 G1 (STEREO) will be visible from Cambridge day-by-day through its apparition:

Date Constellation Comet visibility
28 Mar 2009PegasusNot observable
30 Mar 2009PegasusNot observable
01 Apr 2009PegasusNot observable
03 Apr 2009PegasusNot observable
05 Apr 2009PegasusNot observable
07 Apr 2009AquariusNot observable
09 Apr 2009AquariusNot observable
11 Apr 2009AquariusNot observable
13 Apr 2009AquariusNot observable
15 Apr 2009AquariusNot observable
17 Apr 2009AquariusNot observable
19 Apr 2009AquariusNot observable
21 Apr 2009AquariusNot observable
23 Apr 2009AquariusNot observable
25 Apr 2009AquariusNot observable
27 Apr 2009AquariusNot observable
29 Apr 2009AquariusNot observable
01 May 2009AquariusNot observable
03 May 2009AquariusNot observable
05 May 2009AquariusNot observable
07 May 2009AquariusNot observable

A more detailed table of C/2009 G1 (STEREO)'s position on each night is available here. A diagram of the orbit of C/2009 G1 (STEREO) is available here.

Finder chart

The chart below shows the path of C/2009 G1 (STEREO) 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/2009 G1 (STEREO) is currently available.

The comet's position at perihelion will be:

Object Right Ascension Declination Constellation Magnitude
Comet C/2009 G1 (STEREO) 22h48m50s 4°32'S Aquarius 9.1

The coordinates are given in J2000.0.

The sky on 7 Jul 2024

The sky on 7 July 2024
Sunrise
05:12
Sunset
20:23
Twilight ends
22:34
Twilight begins
03:01


Waxing Crescent

7%

2 days old

Planets
Rise Culm. Set
Mercury 07:03 14:22 21:42
Venus 05:55 13:27 20:58
Moon 06:30 14:22 22:03
Mars 01:45 08:53 16:01
Jupiter 02:44 10:11 17:37
Saturn 23:23 05:03 10:44
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 05 Jul 2024.

Image credit

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

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