12 December 2007

Comet 17P/Holmes (12 Dec. 2007 UT)

Date: 12 December 2007
Time: 2:05 U.T.
Instrumentation: 20x80 Binoculars
Seeing: Good
NELM: 6.5 or better
Temperature: +21 F (-6 C)


The above sketch shows the full, three degree field of the 20x80 binoculars. North is up. West is to the right. Not all of the field stars that were seen were recorded in the sketch.

Comet Holmes is now clearly larger in apparent size than a full moon. (The apparent diameter of a full moon is about 0.5 degrees, or one-sixth of the binocular field.) As I was observing this comet I was reminded of the general appearance of a fossilized trilobite.

Comet Holmes remains easily visible to the unaided eye. It appeared to be clearly brighter than the nearby Perseus Double Star Cluster.

10 December 2007

Comet Holmes (10 Dec. 2007)

Date: 10 December 2007 U.T.
Time: 2:40 U.T.
Instrumentation: Unaided Eye, 8x42 & 20x80 Binoculars
Seeing: Good
NELM: 6.5
Temperature: +15 F (-9 C)

Comet Holmes continues to be easily visible to the unaided eye -- at least from a dark sky. To the unaided eye the comet looks like a round, nebulous patch of light that's somewhat comparable to a full moon in angular size.

With 20x80 binoculars the comet had the appearance of a huge, oval (somewhat egg-shaped) patch of light occupying roughly one quarter of the binocular's three-degree field of view. The comet's sunward side was somewhat better defined than its fuzzier, anti-sunward side. Gone is the distinction between an inner and outer coma. The previously visible outer coma has probably enlarged and faded too much for my eyes to notice. No tail was noticed.

Within the comet's coma was a distinctly brighter bar of light. The bar was brightest and widest on its sunward end. Several stars were visible through the comet's coma. The comet's pseudo-nucleus was not visible. Comet Holmes now has the appearance of a giant, celestial Easter egg.

The view with 8x42 binoculars was essentially a smaller version of the 20x80 binocular view. At this point in time binoculars probably provide better views of this comet than most telescopes can provide.

I've made a few other observations of Comet Holmes between this blog entry and my previous blog entry; but other interests, activities, and necessities have taken precedence over blogging. Such is life . . .