Taghimmelkomet C/2012 S1 ISON

[Astrofan80]

Leider verdichten sich die Annahmen, dass ISON nur noch aus einer Staubwolke besteht.

http://groups.yahoo.com/neo/groups/comet...ages/22488

No good news from STEREO-A. Matthew Knight has sent me his photometry of
spacecraft images to 15UT 25. Nov. They well corresponds to latest
visual observations. After strong fade, comet has started to gaining
brightness again. Unfortunately with speed far bellow (n=0.66)
brightening for simple reflecting body (n=2). If we assume that all
brightness coming from dust cloud, there is nothing inside coma that can
resupply dust to coma at least on same level. What is worst, deviation
from average activity level keep growing. Such characteristic more
corresponds to slowly scattering dust cloud, then intact comet.

Der Komet ist nun im Korona-Gesichtsfeld von STEREO-A aufgetaucht und seit gestern nur wenig heller geworden.