Cbet nr. 3238, issued on 2012, September 24, announces the discovery of a new comet (discovery magnitude 18.8) by Vitali Nevski (Vitebsk, Belarus) and Artyom Novichonok (Kondopoga, Russia) on CCD images obtained on Sept. 21.06 UT with a 0.4-m f/3 Santel reflector of the International Scientific Optical Network (ISON) near Kislovodsk, Russia. The new comet has been designated C/2012 S1 (ISON).

Comet C/2012 S1 (ISON) will get to within 0.012AU of the Sun (extremely close) at the end of November 2013 and then to ~0.4AU from Earth at the beginning of January 2014! According to its orbit, this comet might become a naked-eye object in the period November 2013 - January 2014. And it might reach a negative magnitude at the end of November 2013.

We performed some follow-up measurements of this object, while it was still on the neocp. Stacking of 24 unfiltered exposures, 120-sec each, obtained remotely on 2012, September 22.4 from H06 (ITelescope network near Mayhill, NM) through a 0.25-m, f/3.4 reflector + CCD, shows that this object is slightly diffused, with a 5" coma. The FWHM of this object was measured about 15% wider than that of nearby field stars of similar brightness.

Our confirmation image
Here you can see an animation showing the movement of the comet in about 30 minutes

M.P.E.C. 2012-S63 assigns the following nearly parabolic (e = 0.999999964) orbital elements to comet C/2012 S1 (ISON): T 2013 Nov. 28.87; e= 0.99; Peri. = 345.56; q = 0.012 AU; Incl.= 62.36.

Below you can see a graph generated using the software Orbitas and showing the predicted magnitude (in red) versus the elongation (click on the image for a bigger version):
Ephemeris for this comet can be seen here.