Re: Change in appearance of 17P/Holmes?
- I hasten to point out that it appears the diffuse mass being descibed
as the "coma" of 17/P is, since the last full moon, likely only a
faction of that previously seen. In late January and early February,
before moonlight began to interfere, coma diameters in the order of 80'
up to 120' were being reported and the coma was growing progressively
larger, inspite of its increasing distance from Earth. Now, quite
suddenly, what is being reported in the way of coma diameters seems
typically only about 60'.
Considering that the former "tail" (which it probably was not, in the
usual sense) was a part of the outer perimeter of the original
elongated coma, its outer-most regions likely have just faded to the
degree that they have been lost to the sky background. The coma's
former elongated shape has not truly transitioned and/or shrunk (which
would be difficult to explain) into a more circular outline but rather
what was visible of reported coma has changed, by virtual of the
comet's fading and dissapation.