7,377 days ago
Dominic Ford, Editor
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Comet C/2004 Q2 (Machholz) is forecast to reach the brightest point in its 2005 apparition on 1 January. At that time, it will lie at a distance of 1.21 AU from the Sun, and at a distance of 0.25 AU from the Earth.
From Cambridge on 1 January it will be visible in the evening sky, becoming accessible around 17:30 (EDT), 37° above your eastern horizon, as dusk fades to darkness. It will then reach its highest point in the sky at 22:07, 84° above your southern horizon. It will continue to be observable until around 04:58, when it sinks below 15° above your north-western horizon.
The events that comprise the 2004–2005 apparition of C/2004 Q2 (Machholz) are as follows:
Date | Event |
30 Dec 2004 | Comet C/2004 Q2 (Machholz) passes perigee |
01 Jan 2005 | Comet C/2004 Q2 (Machholz) reaches peak brightness |
15 Jan 2005 | Comet C/2004 Q2 (Machholz) passes perihelion |
The table below lists the times when C/2004 Q2 (Machholz) will be visible from Cambridge day-by-day through its apparition:
Date | Constellation | Comet visibility |
11 Dec 2004 | Lepus | Visible from 20:23 until 03:52 Highest at 00:07, 35° above S horizon |
13 Dec 2004 | Orion | Visible from 19:55 until 03:53 Highest at 23:54, 37° above S horizon |
15 Dec 2004 | Orion | Visible from 19:30 until 03:58 Highest at 23:44, 40° above S horizon |
17 Dec 2004 | Orion | Visible from 19:03 until 04:04 Highest at 23:34, 44° above S horizon |
19 Dec 2004 | Orion | Visible from 18:36 until 04:11 Highest at 23:23, 47° above S horizon |
21 Dec 2004 | Orion | Visible from 18:07 until 04:18 Highest at 23:13, 52° above S horizon |
23 Dec 2004 | Orion | Visible from 17:37 until 04:26 Highest at 23:02, 57° above S horizon |
25 Dec 2004 | Orion | Visible from 17:05 until 04:35 Highest at 22:50, 62° above S horizon |
27 Dec 2004 | Taurus | Visible from 17:04 until 04:46 Highest at 22:39, 68° above S horizon |
29 Dec 2004 | Taurus | Visible from 17:04 until 04:58 Highest at 22:27, 74° above S horizon |
31 Dec 2004 | Auriga | Visible from 17:06 until 05:12 Highest at 22:14, 80° above S horizon |
02 Jan 2005 | Auriga | Visible from 17:07 until 05:28 Highest at 22:01, 86° above S horizon |
04 Jan 2005 | Auriga | Visible from 17:10 until 05:49 Highest at 21:48, 88° above N horizon |
06 Jan 2005 | Auriga | Visible from 17:12 until 06:17 Highest at 21:34, 82° above N horizon |
08 Jan 2005 | Camelopardalis | Visible from 17:15 until 06:26 Highest at 21:20, 77° above N horizon |
10 Jan 2005 | Camelopardalis | Visible from 17:19 until 06:24 Highest at 21:04, 72° above N horizon |
12 Jan 2005 | Camelopardalis | Visible from 17:22 until 06:22 Highest at 20:48, 68° above N horizon |
14 Jan 2005 | Camelopardalis | Visible from 17:26 until 06:20 Highest at 20:32, 64° above N horizon |
16 Jan 2005 | Camelopardalis | Visible from 17:30 until 06:18 Highest at 20:13, 61° above N horizon |
18 Jan 2005 | Camelopardalis | Visible all night Highest at 19:54, 58° above N horizon |
20 Jan 2005 | Camelopardalis | Visible all night Highest at 19:33, 56° above N horizon |
A more detailed table of C/2004 Q2 (Machholz)'s position on each night is available here. A diagram of the orbit of C/2004 Q2 (Machholz) is available here.
Finder chart
The chart below shows the path of C/2004 Q2 (Machholz) 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/2004 Q2 (Machholz) is currently available.
The comet's position on 1 January 2005 will be:
Object | Right Ascension | Declination | Constellation | Magnitude |
Comet C/2004 Q2 (Machholz) | 05h10m00s | 37°13'N | Auriga | 3.0 |
The coordinates are given in J2000.0.
The sky on 14 Mar 2025
The sky on 14 March 2025 | ||||||||||||||||||||||||||||||||||
99% 14 days old |
All times shown in EDT.
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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.