Comet C/2008 A1 (McNaught) passes perihelion

Dominic Ford, Editor
From the Comets feed


Comet C/2008 A1 (McNaught) will make its closest approach to the Sun on 29 September, at a distance of 1.09 AU.

From Cambridge on the day of perihelion it will not be readily observable since it will lie so far south that it will never rise more than 20° above the horizon.

The events that comprise the 2008 apparition of C/2008 A1 (McNaught) are as follows:

Date Event
17 Sep 2008Comet C/2008 A1 (McNaught) reaches peak brightness
29 Sep 2008Comet C/2008 A1 (McNaught) passes perihelion

The table below lists the times when C/2008 A1 (McNaught) will be visible from Cambridge day-by-day through its apparition:

Date Constellation Comet visibility
08 Sep 2008CentaurusNot observable
10 Sep 2008CentaurusNot observable
12 Sep 2008CentaurusNot observable
14 Sep 2008CentaurusNot observable
16 Sep 2008CentaurusNot observable
18 Sep 2008CentaurusNot observable
20 Sep 2008CentaurusNot observable
22 Sep 2008CentaurusNot observable
24 Sep 2008CentaurusNot observable
26 Sep 2008HydraNot observable
28 Sep 2008LibraNot observable
30 Sep 2008LibraNot observable
02 Oct 2008LibraNot observable
04 Oct 2008LibraNot observable
06 Oct 2008LibraNot observable
08 Oct 2008LibraNot observable
10 Oct 2008LibraNot observable
12 Oct 2008LibraNot observable
14 Oct 2008ScorpiusNot observable
16 Oct 2008ScorpiusNot observable
18 Oct 2008ScorpiusNot observable

A more detailed table of C/2008 A1 (McNaught)'s position on each night is available here. A diagram of the orbit of C/2008 A1 (McNaught) is available here.

Finder chart

The chart below shows the path of C/2008 A1 (McNaught) 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/2008 A1 (McNaught) is currently available.

The comet's position at perihelion will be:

Object Right Ascension Declination Constellation Magnitude
Comet C/2008 A1 (McNaught) 15h14m10s 26°45'S Libra 7.1

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

99%

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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