Comet ISON Image of the Week

Where it all began... (July 1, 2013)

This is where it all began: the so-called "discovery image" of Comet C/2012 S1 (ISON), taken on September 21, 2012 by astronomers Vitali Nevski and Artyom Novichonok. They captured the comet using a 40-cm (16-inch) telescope in Russia that is part of the International Scientific Optical Network, or "ISON", hence the name. The ISON network is typically used for observing space debris and asteroids but programs such as this often get the added bonus of discovering the occasional comet, too!

Within a couple of days of Novichonok and Nevski reporting this find, other observatories had successfully located the comet, which was currently at an extremely faint magnitude 18. Further to this, Comet ISON was subsequently located in images taken several months prior in archived data taken by the Mount Lemmon Survey and Pan-STARRS programs. This is known as "pre-covery" and is quite common. Very faint comets can be hard to spot unless you know exactly where in your data to look, and so many of these sky survey programs take large numbers of images for which there are simply not enough man-hours to individually scour in great detail.

By September 24, 2012, Comet ISON had received an official designation of C/2012 S1 (ISON), and a preliminary orbit determination that classified it as a Sungrazing Comet, bringing it to within about 1.1-million miles of the Sun on November 28, 2013.

Every week this year we will put up a new image related to Comet C/2012 S1 (ISON). If you have a cool image you'd like us to consider, please send it to, along with a description and any credits you would want applied. We'll contact you if we choose to use your image on the CIOC Website.

See our ISON Image of the Week Archives for earlier picks!