Comet Holmes Update

A news story in the November 2007 The Citizen Scientist described the extraordinary brightening of Comet 71P/Holmes in late October (Comet Holmes Bursts Into View).

Comet Holmes usually receives little notice while it orbits the sun every seven years. But on October 24, the comet burst on the scene when it suddenly brightened by hundreds of thousands of times and became easily visible to the unaided eye.

By mid-November, Comet Holmes exceeded the apparent size of the moon. Of course the comet is not as bright as the moon, for it is made visible only by sunlight scattered from its veil of dust known as a coma. The comet has been easily visible through binoculars, and it's large, fuzzy appearance sharply contrasts with nearby stars. But it will dim as the moon grows brighter

Figure 1. Comet Holmes as photographed by Bob Townsend.

Thanks to astrophotographer Bob Townsend for sending the excellent photograph of Comet Holmes in Fig. 1. Bob sent these details about the image:

"I used my Takahashi E200 800mm focus F4 hyperbolic astrograph and spectrum modified Canon 350D DSLR on my homemade German equatorial mount. This exposure is a composite of 8x20 sec, 8x40 sec, 8x 80 sec, 8x 120 sec, 8x 240 sec, and 13x 600 sec. The raw images were converted and calibrated with Images Plus with later processing in Photoshop."

Many astronomy web sites are posting updates about Comet Holmes, including Sky & Telescope magazine, a NASA-sponsored site and others.

Forrest M. Mims III.