Long live Comet ISON, Comet ISON is dead.
I watched NASA’s live webcast of their various imagers pointed at the sun for Comet ISON’s perihelion, including the real-time data from the SDO, or Solar Dynamics Laboratory (actually a 9-minute delay; 6 minutes for data to travel 3/4 of the way from the sun, and 3 minutes for data processing and upload). As all these scientists sat around theorizing about what might explain Comet ISON’s absence from the SDO imagery, I found this movie showing it:
http://stereo-ssc.nascom.nasa.gov/browse/2013/11/28/ahead_20131128_cor2_512.mpg
Comet ISON can be seen close to perihelion, and then hitting what appears to be a Coronal Mass Ejection (CME). It immediately shatters and vaporizes, practically disappearing over the course of about an hour. It appears this may have happened prior to coming into view of the SDO imagers, unfortunately. This is very low-resolution beacon data from far out in space, and I believe once they receive all the high-resolution data that NASA will have a high-res view of this comet’s death.

Comet ISON shatters upon hitting CME.
Happy Thanksgiving everyone!