Unexpected comet 'outburst' could be visible for weeks

Saturday, October 27, 2007

Comet Holmes photographed on Oct 25,2007, 7:19 UT from Minneapolis, Minnesota.
Image: Tomruen.

If you've noticed a fuzzy yellowish object at night in the northeast sky, immediately to the left of the constellation Perseus, that's because it is the Comet Holmes which has suddenly gotten brighter in what scientists say is "absolutely unprecedented" in comet research.

Earlier reports were that the object might have been a star that went super nova, or that a new star might have formed, but because the comet does not have a tail, the earlier reports were later dismissed.

"This is a terrific outburst, and since it doesn't have a tail right now, some observers have confused it with a nova. We've had at least two reports of a new star. When the Deep Impact probe hit Comet 9P Tempel, there was almost no change in brightness. This outburst by Comet Holmes is extreme!" said Minor Planet Center director, Brian Marsden.

Not more than a few days ago, the comet began to get brighter and appear larger in the sky, in what scientists call an "outburst." The comet is usually only visible through telescopes, but the outburst has caused it to be visible through the naked eye and it will continue to grow brighter with its coma eventually reaching the size of The Moon. Currently, only people living in the Northern Hemisphere are able to get a glimpse of the show. Binoculars and a small telescope can be used to get a close up view.

Orbit of Comet Holmes.
Image: Tomruen.

The comet took just 24 hours to get more than 400,000 times brighter than it usually is, and is currently over one million times brighter, but Marsden says the comet's brightness could dim in days or even weeks.

The comet was discovered on November 6, 1892 by Edwin Holmes while he was looking at the Andromeda Galaxy through his telescope. Researchers say that the comet may also have had an outburst at the time it was discovered. It was seen once after that in 1899 and then 1906, but disappeared until it was "rediscovered" in 1964 after a prediction Marsden had made.

"Since then, it’s been behaving well – until now," added Marsden.