Comet ISON Starting To Fizzle Out
August 20, 2013

Astronomer Captures Faint Comet ISON

[ Watch the Video: ScienceCasts: Comet ISON to Fly By Mars ]

Lee Rannals for - Your Universe Online

New observations of the highly anticipated Comet ISON have shown this year's fall spectacle might not be as spectacular as we hoped.

According to Sky & Telescope, amateur imager Bruce Gary in Arizona has become the first astronomer to pick up Comet ISON after it was hidden behind the Sun for a two-and-a-half month period. Gary pointed his 11-inch telescope about six degrees above the eastern dawn horizon and was able to record a fuzzy point with an anti-sunward tail at the comet's exact predicted position.

Sky & Telescope reported the comet is about 2 magnitudes fainter than the comet should be, according to previous predictions. So far, it has not improved on the two-magnitude deficit the comet was showing at the end of May before it tucked itself behind the sun away from our view.

"ISON is currently about at the distance from the Sun where water ice sublimation would be expected to be taking over in the comet's photometric development," comet analyst John Bortle told Sky & Telescope. "That the comet continues to appear as faint as it does implies that its intrinsic brightness (absolute magnitude) is low and that the nucleus is probably small and relatively inactive."

Bortle went on to say "new" comets like ISON have turned out to be pretty lackluster, and "with very few exceptions, these comets brighten only very slowly."

"So... things are looking ever more bleak for chances of any grand display to be put on by ISON come this December. Still, I wouldn't fully commit to such until I see some actual visual observations reported," Bortle concluded.

Scientists have been warning all along that comets can be notorious for fizzling out before their big show. Comet ISON was positioned to give a great show this fall, with some predictions even saying the comet would be able to be seen in daylight with the naked eye.

The comet will be approaching within about 730,000 miles of the Sun by November. Scientists said the comet had the potential to become among the brightest comets of the last 50 years. However, Don Yeomans of NASA Near-Earth Object Program wasn't quite buying into the hype of Comet ISON at the time.

“Comets are notoriously unpredictable,” said Yeomans. “I'm old enough to remember the last 'Comet of the Century'. It fizzled.”