The Great Christmas Comet of 2011, 2011 W3 (Lovejoy) Options

[Guest_Sunspot_*]

http://sungrazer.nrl.navy.mil/index.php?p=.../birthday_comet

Possible very bright sungrazing comet coming mid December - Comet Lovejoy C/2011 W3 (Lovejoy)

Information in the link above.

[Mongo]

Commentary by John Bortle (comet-ml post #19037) on the photo just above this post, by Lester Barnes:

I am particularly taken by this latest image in that it almost precisely replicates images of Comet Ikeya-Seki from 1965. The match is nearly exact, right down to the distinctly brighter tail edges, the twists in the tail and even the faint outer sheath enveloping the bright dust tail. Such a feature was also seen in some of the drawings of the Great September Comet of 1882. Truly, Kreutz sungrazers are a group of comets absolutely unique unto themselves!

There seems to be some panic arising among folks currently experiencing cloudy skies down under, thinking that they may miss the whole show. Fear not, for as I pointed out previously although the comet's head will continue to fade rapidly, the tail will drop in brightness far more slowly. If it should follow the evolution of the tail of Ikeya-Seki, then the outer-most portion of the long dust tail will hardly fade at all over the next couple of weeks. However, the tail's middle section will, until it has faded to match the end portion. Then the entire tail will seem to fade as a unit. Remember too, that the tail will be continuing to grow throughout the period. I would anticipate the it might attain a final naked eye length of ~25 degrees, by which time it will be very faint and difficult ghostly specter to the naked eye.

I was interested to hear that David S. reports variations in the brightness of the tail over the course of a short time, a phenomenon referred to a coruscation. Such has been reported on rare occasions throughout cometary history. Although usually attributed to atmospheric instability, some instances have been much harder to explain as such and if seen, it should always be recorded, along with details of the prevailing weather conditions.

J. Bortle