Calculations show that the celestial visitor could be dazzlingly bright in November 2013 and be easily visible in broad daylight as it rounds the Sun. Comet ISON is so named because it was first spotted on photos taken by Vitali Nevski and Artyom Novichonok from Russia using the International Scientific Optical Network telescope...
That makes it a type of comet called a sungrazer, and there is a risk that the comet - essentially a giant ball of rock and ice, will break up when it makes that close approach.
But it could become brighter than the greatest comet of the last century, Comet Ikeya-Seki, which excited astronomers in 1965...The article at The Telegraph indicates that this comet should be "fifteen times brighter than the moon."
Comet ISON, which has the official label C/2012 S1, appears to be on a nearly parabolic orbit which leads scientists to believe that it is making its first trip through the Solar System. This means it may have been dislodged from a vast reservoir of icy debris surrounding the Sun far beyond the planets, called the Oort Cloud. It is a giant ball of rock and ice that is likely to be packed with volatiles including water ice that will erupt as brilliant jets of gas and dust when it is at its best.
Addendum November 2013:
A new article in The Telegraph reports that the comet is now visible to the naked eye:
The comet has dramatically brightened with an outburst of gases in recent days as it draws ever closer to the sun, the Times reported, and if it survives it could be the greatest celestial display in more than 300 years. It is now visible to the naked eye and is expected to continue brightening over the next few weeks until it outshines the moon...
If predictions are correct the galactic show will rival the Great Comet of 1680, which had a tail 90 million miles long and could be seen during the day because it was so bright, leading many to think it was a punishment from God. Even if Ison breaks up before then, or fails to survive its perihelion, its closest scrape with the sun, experts believe its death throes could be spectacular...
If the comet – which is best observed through a telescope or strong binoculars – survives its scrape with the sun it will reach its most brilliant in early December.Please read Danack's comment from last fall regarding the size and location of the comet.
The photo, from NASA, shows Comet McNaught ("the Great Comet of 2007")-
Within the next two weeks of 2013, rapidly brightening Comet ISON might sprout a tail that rivals even Comet McNaught.More info from NASA here (and undoubtedly more to come in the next few weeks)
I've been looking forward to this but a couple of notes:
ReplyDelete* because it's going to be so close to the Sun at it's brightest, it will only be that bright either very close to dawn or sunset. Unfortunately it won't be hanging high in the night sky to be easily seen like comet Hale-bopp.
Although it will be brighter than the moon, it will only be the comets core that will be that bright, so the bright bit will only appear as a point in the sky, so it won't be like a 2nd moon lightning up the night sky.
But I'm hoping the brightness of the core of the comet won't be the most visible feature.
There's a reasonable chance that this is the first time this comet will have entered the solar system which would mean that it would be rather light - i.e. made up of water, gas and dust, rather than metal and rock.
The comet is going to pass really quite close to the sun and so like the comet grazer comet earlier this year http://en.wikipedia.org/wiki/C/2011_W3_(Lovejoy) could produce a large tail as the sun boils away the comets surface.
Unfortunately that would require a trip to the northern hemisphere to view it after it passes the Sun.
Thank you for that info, Danack. I was kind of wondering how they were defining "brightness."
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ReplyDeletehttp://www.solarsystemscope.com/ison/
This visualizer can show both space and Earth views of ISON's trajectory. If the comet doesn't break up as it rounds the Sun, and if it's bright (it could easily deliver a dud considering all we don't know about it), it will be visible in the northern sky all night long as it recedes from the Sun. As to it being visible during the day, I agree that only the comet's core has much potential to be bright enough for that.
Sky and Telescope is not as optimistic:
ReplyDelete"There never was anything to the early hysteria that it would dazzle the world 100 times brighter than the full Moon (though some media still can't resist wild hype; the U.K's Telegraph is headlining it as late as November 18th as a "Once in a lifetime galactic fireworks display"). Do, however, plan to go out for a fascinating dawn observing project on any clear morning now, at least for binoculars and wide-field telescopes — and especially in early December. "
Do you know where in the sky to look? If it's peri-solar, then presumably it would be near the eastern horizon in the morning (and follow the sun through the day, but be hard to spot midday)?
DeleteLook toward Spica in the early morning hours, Stan. It's been too light and overcast here to see it, but look eastward near Virgo around 4:00 am or so if you have a clear (and preferably dark) sky.
ReplyDeleteWell, it turns out it was the Great Nothing Burger of 2013.
ReplyDeleteIs this something to worry about?
ReplyDeleteNot at all. As per Danack's comment, it's apparently fizzling out as it rounds the sun.
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