Comet ISON peaks as it rounds the Sun

Comet ISON continues on its way to the Sun. Recent observations have hinted at a possible breakup of the comet and it is still uncertain as to whether or not ISON will survive it's trip around the Sun. Only a few weeks ago astronomers measured ISON's diameter to be about 3 miles - large enough to take the intense heat and extreme pull of the Sun's gravity. But new data shows ISON at only 3/4 to 1 mile wide.

Viewing ISON is getting to be really difficult. Although the comet has brightened twice in the last few days and is now recorded at magnitude 4.0 - 4.5 she is also very close to the Sun and hence low to the horizon in the pre-dawn glow. ISON may shine at magnitude -4.0 at perihelion which occurs about midday on Thanksgiving day (about as bright as Venus). Under optimum conditions (and very careful observation techniques!) ISON could be visible to the naked eye.

But the best views of perihelion likely will come from a trio of solar telescopes located outside Earth’s atmosphere. The Solar Terrestrial Relations Observatory (STEREO), the Solar Dynamics Observatory (SDO), and the Solar and Heliospheric Observatory (SOHO) each supply different perspectives.

More details on this and a really cool photo of ISON is available on the Astronomy Magazine's website. Sky&Telescope has some suggestions if you really want to try to see ISON at perihelion.