Comet ISON ObservationSubmitted by emalvini on Wed, 11/20/2013 - 00:43
Comet ISON Observation
It may be visible in the early morning hours (before sunrise) now in the southeastern sky....but looks like we will have plenty of time to observe this comet.
The comet is at its closest to the Sun (perihelion) on 28 November (Thanksgiving Day in the USA), when it is just a million km or so above our star. It had been thought that if the comet’s brightness increased according to the most optimistic predictions on this day it might be possible to see the comet in the daytime. The comet’s failure to get brighter at the rate originally predicted means it will probably be impossible to view it like this.
What happens during this phase of the comet’s orbit determines how visible it will appear to us. The intense radiation of the Sun will cause material to explosively evaporate off the comet. This could mean the comet will rapidly brighten and develop a more impressive tail, delighting observers. In the worst case, the comet will disintegrate when it is at its closest to the Sun, turning into a plume of debris that will rapidly disperse. If this happens I am afraid this will be the end of the show for amateur observers.
During December 2013 we should be able to see Comet ISON in both the morning and evening sky as it races through the constellations. In early December it will be between between Libra and Ophiuchus, a couple of weeks later it will be between Serpens and Hercules, on 22 December it will be in Hercules near the globular cluster M13. By 25 December it will be close to the Plough, and is circumpolar from UK and Ireland, meaning it will be in the sky all night long. On 26-27 December, ISON will be at its closest to Earth at 64 million km. At the end of December the comet is in Draco and will be visible in the north west by evening, in the morning sky before before sunrise in east. The comet will be fading, but will hopefully be still naked eye visibility.