The great cometary show

Jan 19, 2007
The great cometary show
The extended tail of Comet McNaught, seen from Paranal, observed in the evening of Jan. 18, 2007, when the comet was setting behind the Pacific Ocean. The planet Venus is visible in the lower right of the image. Credit: ESO

Comet McNaught, the Great Comet of 2007, is no more visible for observers in the Northern Hemisphere. It does put an impressive show in the South, however, and observers in Chile, in particular at the Paranal Observatory, were able to capture amazing images, including a display reminiscent of an aurora!

Comet C/2006 P1 was discovered in August 2006 by Robert McNaught on images taken by D. M. Burton with the 0.5-m Uppsala Schmidt telescope in the course of the Siding Spring Survey (Australia). It is one of 29 comets discovered by this telescope since early 2004 in a project to systematically search the southern skies for asteroids, or comets, that can pass close to the Earth. At that time, the comet was only a very faint, barely diffuse object, about 50 000 times fainter than what the unaided eye can see.

However, as the comet came closer to the Sun, it brightened rapidly, in such a way as to become easily visible with the unaided eye in early January 2007, becoming brighter than Comet Hale-Bopp and Comet West, thereby earning its title of Great Comet of 2007. It even became the brightest comet in more than 40 years.

Comet McNaught had its closest approach to the Sun on 12 January, being well inside the orbit of Mercury, with a minimum distance of only 17% the mean Earth-Sun distance. On January 13, it reached its maximum brightness when it was possibly brighter than Venus.

In early January, it was visible in the northern hemisphere but after passing the Sun, it only became visible from the southern hemisphere, entering the constellation Microscopium (The Microscope) on 18 January.

Astronomers in ESO's observatories in Chile are thus optimally placed to enjoy the show and certainly do not want to miss it. The comet displays a vivid coma and a lovely, sweeping tail.

As the night deepens, and the comet had set, it revealed a sweeping fan that gives onlookers the impression they are witnessing an aurora, albeit the phenomenon is completely different. The structure in the tail is probably the fingerprint of past bursts of activity of the comet, releasing small dust particles whose paths are deflected by the solar light.

The comet is now heading further south and should still be nicely visible for southern observers for several days.

Source: European Southern Observatory

Explore further: Image: Hubble serves a slice of stars

add to favorites email to friend print save as pdf

Related Stories

Comfortable climate indoors with porous glass

29 minutes ago

Proper humidity and temperature play a key role in indoor climate. In the future, establishing a comfortable indoor environment may rely on porous glass incorporated into plaster, as this regulates moisture ...

Alcatel loss narrows in 2Q but revenue stagnates

39 minutes ago

(AP)—Telecommunications equipment company Alcatel-Lucent SA says its net loss narrowed in the second quarter thanks to lower accounting charges, while revenue stagnated and restructuring charges mounted.

Simulation models optimize water power

39 minutes ago

The Columbia River basin in the Pacific Northwest offers great potential for water power; hydroelectric power stations there generate over 20 000 megawatts already. Now a simulation model will help optimize the operation ...

Recommended for you

Image: Hubble serves a slice of stars

1 hour ago

The thin, glowing streak slicing across this image cuts a lonely figure, with only a few foreground stars and galaxies in the distant background for company.

Evidence of a local hot bubble carved by a supernova

21 hours ago

I spent this past weekend backpacking in Rocky Mountain National Park, where although the snow-swept peaks and the dangerously close wildlife were staggering, the night sky stood in triumph. Without a fire, ...

Astronomers measure weight of galaxies, expansion of universe

Jul 30, 2014

Astronomers at the University of British Columbia have collaborated with international researchers to calculate the precise mass of the Milky Way and Andromeda galaxies, dispelling the notion that the two galaxies have similar ...

Mysterious molecules in space

Jul 29, 2014

Over the vast, empty reaches of interstellar space, countless small molecules tumble quietly though the cold vacuum. Forged in the fusion furnaces of ancient stars and ejected into space when those stars ...

User comments : 0