Daytime Binocular Comet!

Date: 12 January 2007 U.T.
Time: 18:50 U.T. (11:50am local)
Binoculars: 20x80 and 8x42
Seeing: Good
NELM: Daytime! in highly transparent sky
Temperature: +5 F (-15 C)


WARNING!! CAUTION!! NEVER look at or toward the Sun with a telescope or binoculars. If the Sun crosses your field of view eye damage or blindness is VERY likely to occur.

As a practicing amateur astronomer since the late 1960s, I've read much on the subject; and I've accumulated a fair amount of experience. Precautions were taken in today's observation that made it physically impossible for me to catch even an accidental glimpse of the Sun while searching for Comet McNaught in the daytime sky.

With the above caution and qualifications in mind, I searched for Comet McNaught in the daytime sky with the aid of 8x42 binoculars. Initially this search was unsuccessful. I switched to 20x80 binoculars. Unlike my 8x42s, my 20x80s have individually focussing eyepieces. This means that the 20x80s were alreadly 'locked' into focus for objects at infinity (Comet McNaught in the evening sky was the last object I had focused on).

I was surprised not only at the brightness of Comet McNaught as seen in the daytime with the 20x80 binoculars, but also at the amount of detail that was visible. The inner portion of the comet's tail was easily visible in the 20x80s! The comet was a very pure white in color. It looked somewhat like a white feather against the deeper blue sky.

The above sketch shows the comet as I saw it with the 20x80s near 12:00 noon. I estimate that I was seeing approximately 15 arcminutes (maybe more) of the comet's tail -- in broad daylight! The observation was made at 18:50 U.T.

After spotting Comet McNaught with the 20x80s I was eventually able to see it with the 8x42s as well. The tail was also visible in the smaller binoculars.

I tried to spot Comet McNaught with the unaided-eye, but was not successful. I judged the comet as "easy" to see with the 20x80s. It wasn't difficult to see with the 8x42s; but it was difficult for the eye to initially acquire.