Comet ISON Tuesday 19th November 2013

Comet ISON, also known  as C/2012 S1 is a sungrazing comet discovered on 21 September 2012 by Vitali Nevski, and Artyom Novichonok.  Comet ISON’s nucleus is around 5 kilometers (3.1 miles) in diameter. Comet ISON  orbit will come to perihelion (closest approach to the Sun) on 28 November 2013 at a distance of 1,860,000 km; or 1,150,000 miles from the center point of the Sun. Its trajectory appears to be hyperbolic, which suggests that it is a dynamically new comet coming freshly from the Oort Cloud. On its closest approach, Comet ISON will pass about 64,210,000 km; 39,900,000 miles from Earth on 26 December 2013.


Comet ISON/2012 S1 is expected to be brightest around the time it is closest to the Sun; however, it may be less than 1° from the Sun at its closest, making it difficult to see against the Sun's glare. In December, Comet ISON  will be growing dimmer, but, assuming that it remains intact, it will be visible from both hemispheres of Earth, possibly with a long tail. Comet ISON  will be well placed for observers in the northern hemisphere during mid to late December 2013.  After perihelion, it will move north on the celestial sphere, passing within two degrees of Polaris on 8 January.