Surely it was a Mr./Mrs. Ison who discovered it? But no, it was actually Vitali Nevski (Виталий Невский, Vitebsk, Belarus) and Artyom Novichonok (Артём Новичонок, Kondopoga, Russia). At least they are receiving credit for initial discovery. ISON stands for the International Scientific Optical Network, an open network of facilities, researchers and personal organized around the discovery and study of bright objects such as comets. Other observers following up on the Near Earth Objects Confirmation Page (NEOCP) at the Minor Planet Center had already reported the appearance, leading to the comet being named after ISON, rather than for Nevski and Novichonok.
Nevski and Novichonok were using the 40-cm reflector at Kislovodsk Observatory in Russia in the early morning hours of September 21st, 2012. They were collecting images in the Gemini and Cancer region, and after running the images through CoLiTec, a program used to detect asteroids and comets in a series of images, Nevski spotted the comet now known as ISON. It was a fairly bright object, with slow movement, suggesting that it was outside the orbit of Jupiter. At this point they notified the Central Bureau of Astronimical Telegrams, who placed the object on the NEOCP for independent confirmation.
Conformitory images were acquired by O. Burhonov at the Majdanak Observatory in Uzbekistan on 1.5m reflector.
Archived images from Mount Lemon Survey and Pan-STARRS 1, taken in the previous January and December were retrieved by G. V. Williams.
It was not until September 23rd, 2012, that excitement over the find began to build. Maik Meyer of Germany, made initial calculations suggesting the object may make a close approach to the sun. Subsequent revisions of the orbit from new incoming data allowed Meyer to mark November, 2013 for the comets perihelion – it’s closest approach to the sun. (Now calculated as November 28th)
For the latest on Comet ISON, check the Comet ISON page on Comet Informer.