This website is a record of observations of Comet C/2012 S1 (ISON) by amateur Bruce Gary, using a Celestron 11-inch telescope at the Hereford Arizona Observatory (G95). When I was the first to obtain a "recovery image" of the comet on August 12, after it had been unobservable during June/July, and when I noted that it was fainter than expected, an unexpected amount of publicity for this web page occurred. I therefore feel obligated to maintain this web site with observations and analyses worthy of that attention. My long-term goal used to be a monitoring of the coma by measuring brightness versus diameter at 3 wavelengths (g'r'i') with a goal of detecting brightness outbursts caused by temperature-dependent volatile activity. Measurements on several dates (after reappearing from behind the sun) show that the comet is brightening at a lower rate than expected, as if the activity level on the nucleus surface (i.e., Af-rho) is not changing as it approaches the sun. By now ISON has probably passed the "frost line," so why is it unresponsive to the increasing level of solar illumination (and surface temperature)? There may be a wonderfully simple explanation for this, and it predicts a late "coming alive" for this particular comet. The recent "discovery" of a jet feature may be the key in understanding Comet ISON's behavior during the past 7 weeks..... CONT.

Recent Updates:

Sunward Jet Analysis:

Toni Scarmato has enhanced images for which he was a participating observer and found a jet pointed toward the sun......

brucegary.net/ISON/