Comet Holmes grows a tail
Comet Holmes, the oddball comet that erupted into naked-eye visibility almost three weeks ago, now appears in photo imagery to have grown a tail. It's not much as comet tails go. (Here are some photos of Comet McNaught, one of the most spectacular tailed comets in recent years, but hard to see from here when it peaked.)
Holmes' tail is not apparent to the naked eye, and can't readily be seen in binoculars. But long-exposure photography does show a stubby ion tail. It's stubby because it is being blown away from the comet's nucleus - and away from the sun and Earth. So, from our perspective, it looks very short.
More recent images also suggest that a gust of solar wind has actually detached the tail from the nucleus. Here's the Holmes Photo Gallery.
Got 3-D glasses - the kind with red and blue lenses? Try them on this Holmes image.
NEW: Here's the first closeup image of Holmes' nucleus I've seen.
Holmes was unusual from the beginning. It brightened unexpectedly from a dim dot in telescopes on Oct. 23, to a bright fuzzball in the constellation Perseus on Oct. 24. It was easily visible to the naked eye, although it looked not so much like a comet as just another unfamiliar star in Perseus. Scientists could only speculate about what sort of an eruption or collapse on the comet's icy nucleus might have caused such a huge exhalation of gas and dust.
In binoculars it looked like a ball of cotton, or a gray billiard ball. It was simple to find, and lots of casual backyard stargazers got a look at their first naked-eye comet since 1997.
In recent weeks, Holmes has moved slowly higher in the sky, climbing in Perseus toward the W-shaped Cassiopeia, in the northeastern sky in the evening hours. It has also appeared to dim somewhat to naked-eye observers, perhaps as the dust and gas expelled with its initial brightening began to dissipate.
But the tail came slowly, and is still not apparent to casual observers. Fortunately, we have digital telescopic images and the Web.