NEO News (10/25/07) Amazing Comet Holmes

Note: The following is the 10/25/07 Edition of NEO News, an email newsletter distributed by David Morrison.

NEO News (10/25/07) Amazing Comet Holmes

This is a special note to alert you to something you may want to see, especially if you have access to a small telescope.

Approximately 36 hours ago Comet Holmes (a normally inconspicuous Jupiter-family comet with aphelion at the orbit of Jupiter and perihelion at 2.2 AU) brightened by almost a million-fold. This is equivalent to the planet Saturn suddenly becoming as bright as the full moon. On October 23-24, Comet Holmes went from magnitude 17 to magnitude 2.8 in just a few hours, doubling in brightness every half hour. At its discovery in 1892, this comet also underwent a similar sudden brightening, presumably due to a very large ejection of gas and dust.

The comet is now easily visible to the naked eye as a bright yellow "star" in the constellation Perseus. For northern hemisphere observers, it can be seen almost all night, passing nearly overhead. A good source for the latest information is the Sky & Telescope webpage http://www.skyandtelescope.com/observing/home/10775326.html or at http://www.aerith.net/comet/catalog/0017P/2007.html. The best finding chart I have seen is on the Netherlands webpage http://www.shopplaza.nl/astro/.

I looked at the comet about midnight last night from the balcony of my urban townhouse. It was about magnitude three, and at low telescopic power it was conspicuous as a bright yellowish disk, looking almost like a planet. At moderate power the disk resolved into a very bright inner coma and a slightly asymmetric fainter outer cloud, but no tail was visible. I have never before seen anything like it.

David Morrison
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