Astronomers in Japan, Persia and Europe report that Comet 17P/Holmes is undergoing a spectacular eruption. The 17th magnitude comet has brightened by a factor of five hundred thousand or more during the past 24 hours becoming a naked-eye object in the evening sky. Look for a yellow 2.5th magnitude fuzzball in the constellation Perseus after sunset. [sky map] [ephemeris] [3D orbit]

"This is unbelievable!" says Iranian astronomer Babak Tafreshi. "I was amazed to find Comet Holmes so easily with the naked-eye in the light-polluted skies of metropolitan Tehran." Click on Tafreshi's photo to pinpoint the comet:
[link to spaceweather.com]
The outburst may signify a breakup of the comet's core or a rich vein of ice suddenly exposed to sunlight--no one knows. At present the comet looks more like a star than a comet; it does not have a discernable tail, but it might grow one as the outburst continues. Amateur astronomers are encouraged to monitor developments using binoculars and backyard telescopes. Stay tuned for updates!
[link to spaceweather.com]


17P/Holmes

Surprisingly, a great outburst occured on Oct. 24 and now it becomes so bright as 3 mag, visible with naked eyes! Completely stellar, so it looks like a nova. It was observed as 14.5 mag in July, then it had been fading down to 17 mag until mid October as predicted. This comet was also in great outburst at the discovery in 1892 and became so bright as 5 mag. At that time, the comet faded after the first outburst, but soon brightened again in the second outburst. The further brightness is uncertain. But the comet will be observable in excellent condition for a while after this.
[link to www.aerith.net]
[link to www.aerith.net]