The comet ISON (also known as C/2012 S1, or Comet Nevski–Novichonok), was discovered on 21 September 2012 by Vitali Nevski and Artyom Novichono using the 0.4-meter (16 inch) reflector of the International Scientific Optical Network near Kislovodsk, Russia and the automated asteroid-discovery program CoLiTec. After this the comet was located on precovery images by the Mount Lemmon Survey from 28 December 2011 and by Pan-STARRS from 28 January 2012. The discovery was announced by the Minor Planet Center on 24 September. Observations by SWIFT suggest that C/2012 S1's nucleus is around 5 kilometers (3.1 mi) in diameter. This image was taken on November 3rd 2013 between 3:50 and 5:20 LT (1:50 and 3:20 UT)