Comet ISON: Current Status

All of us in the CIOC Team routinely get many, often very similar, questions regarding Comet ISON. Foremost among these are "How bright is Comet ISON right now?" and "How bright will Comet ISON get?". The latter of these we can only guess, but the former is a little more definite. Thus we are using this page to show the latest brightness estimates of Comet ISON, per the plot that you see below. We will update this plot from time-to-time, but keep in mind that observations become sparse when the comet is at solar elongations less than ~45-degrees (meaning it is in the region of the sky close to the Sun). We've indicated this on the plot with the dark gray vertical bars. As we get closer to perihelion, we will update it more frequently as more data become available.

Latest lightcurve for Comet ISON

You will notice that the peak of this plot is not shown. Why? Because it's meaningless right now! The CIOC Team believe that ISON's peak brightness (which will occur in the few hours surrounding perihelion) could be anywhere from magnitude -7 to +5 or more, though our current educated guesses are hovering around -3 to -5.

Certainly if you browse around online you will find references to estimates of magnitude -10 or even -15, and the term "Comet of the Century" has been tossed around with abandon. Those are not the words of the CIOC Team, and while they may perhaps turn out to be true, we think it highly unlikely. More likely, ISON will be one of the brightest comets in the past several years and, thanks to the global astronomy community, we hope one of the most broadly observed comets in history!