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Comets

New ‘Sun-Skirting’ Comet Could Provide Dazzling Display in 2013

25 Sep , 2012 by

2013 is looking to be a promising year for potential naked-eye comets, as a new comet has been discovered that will likely skirt close to the Sun, and could provide a stunning display late next year. The comet, named Comet C/2012 S1 (ISON), as it was discovered by a Russian team at the International Scientific Optical Network (ISON), is currently about the distance of Jupiter’s orbit. But it is projected to come within less than 2 million km from the Sun at perihelion by November 28, 2013. Ernesto Guido and Giovanni Sostero from the Remanzacco Observatory in Italy, along with their colleague Nick Howes from the UK have imaged the comet with the RAS telescope in New Mexico, and say, “According to its orbit, this comet might become a naked-eye object in the period November 2013 – January 2014. And it might reach a negative magnitude at the end of November 2013.”

This new comet joins Comet C/2011 L4 PanSTARRS, which is projected to come within 45 million kilometers (28 million miles) of the Sun on March 9, 2013, which is close enough for quite a bit of cometary ice to vaporize and form a bright coma and tail. Comet PanSTARRS will be visible at perihelion to southern hemisphere, while Comet ISON should be visible to mid-latitude northern hemisphere skywatchers, according to the Remanzacco team.

Orbit diagram from JPL’s Small Body Database of Comet ISON, as of Sept. 25, 2012. Credit: JPL

Right now, Comet ISON is at magnitude +18, and only larger telescopes can see it. How bright will the comet get, and could it even be visible during daytime? That’s the big question which only time will answer. Just 2 million km distant from the Sun is incredibly close, and if the comet stays intact, some estimates say it could reach a brilliant negative magnitude of between -11 and -16. Comparatively, the full Moon is about magnitude -12.7.

But this will happen only if the comet will stay together. Comets can be fairly unpredictable, and other comets that have come that close to the Sun — such as Comet Elenin in 2011, Comet LINEAR in 1999 and Comet Kohoutek in 1973 — failed to live up to expectations of brightness and visibility.

But other comets have survived, like Comet Lovejoy earlier this year, which came two times closer, and Comet McNaught in 2007 which became visible even in daylight when it reached magnitude -5.5. It was not as close to the Sun as Comet ISON will be, however, as McNaught was about 24 million km away.

The discovery of C/2012 S1 (ISON) was made by Vitali Nevski, of Vitebsk, Belarus, and Artyom Novichonok, of Kondopoga, Russia with a 0.4-meter reflecting telescope near Kislovodsk, Russia.

You can see the ephermides of the Comet ISON here, from the Minor Planet Center.

The a Remanzacco Observatory team has more images, including an animation of Comet ISON on their website.

You can see the full visibility calculations of Comet ISON done by Daniel Fischer here.

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By  -        
Nancy Atkinson is currently Universe Today's Contributing Editor. Previously she served as UT's Senior Editor and lead writer, and has worked with Astronomy Cast and 365 Days of Astronomy. Nancy is also a NASA/JPL Solar System Ambassador.



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SJStar
Guest
SJStar
September 25, 2012 6:57 PM
A cautionary tale for the blithering blind media, Ms. Atkinson et al. … Remember the failed Comet Kohoutek in 1973? The media hyped it up and is was visually a dismal failure. It is probably the comet that damaged all visual or public astronomy reputation for many decades. It was reported as the “Comet of the Century!” — ?10 magnitude they said! Absolute piffle! It wasn’t. It was a dud. Yet it too had a close approach at 0.14 AU. It too had a similar inclination and distance. So before you wind us up like a cheap watch, wait until about August 2013 before madly rabbiting on about it possible brilliance. It is promising, if it fails, we’ll… Read more »
Michael Runow
Guest
Michael Runow
September 25, 2012 7:08 PM

She mentioned Kohoutek in the article, which was hardly sensationalistic. Nancy was very clear that we have insufficient information to make predictions of brightness. Still, this one is a lot closer than Kohoutek. 10X closer,100x the intensity.

SJStar
Guest
SJStar
September 25, 2012 7:38 PM

Perhaps, but it depends on the amounts of ices…

All I’m saying is don’t count your chicken before they hatch.

Really is ?11 or ?16 possible or ever observed? Let’s at least be realistic

SJStar
Guest
SJStar
September 25, 2012 7:26 PM

You say; “Just 2 million km distant from the Sun is incredibly close, and if the comet stays intact, it could reach a brilliant negative magnitude of between -11 and ?16.”

Please. This would make it the brightest comet of all time by more than 3 to 8 magnitudes. As you’ve seemingly and brutally deleted my first comment on Kohoutek, please show us the evidence for such a magnitude. I really don’t, frankly, believe it.

Michael Runow
Guest
Michael Runow
September 25, 2012 8:03 PM

The great comet of 1882 was estimated to be -15 to -20 magnitude. You’re trolling a post on a comet? Really?

SJStar
Guest
SJStar
September 25, 2012 9:34 PM
Why is it every time someone makes a comment and someone disagrees with it, your automatically judged as a troll? Estimated magnitudes for comets is dubious at best. Sure some sources quote 17th, but that was just a few short hours against the brilliant glare of the sun. More realistic values or reliable brightness are at best around ?11. It is mostly speculation not a measured value.Yet that is irrelevant… The point is that predicting magnitudes are notoriously wrong and that they are variable due to the composition of the comet, the activity of the sun, the position of the earth, the error in the orbital positions, the size of the comet, etc. This article here is so… Read more »
Michael Runow
Guest
Michael Runow
September 26, 2012 3:08 PM

You’re a troll because you trashed the author while obviously not having even read the entire article.

SJStar
Guest
SJStar
September 26, 2012 10:45 PM

Opportunist comments like this is a kinda trolling too…

Jeanette Dunphy
Guest
September 26, 2012 1:35 AM

Great report Nancy. smile Thanks. I will be sharing.

Nick Howes
Guest
September 28, 2012 11:38 AM
Stuart has raised some very important points. I don’t think it’s trolling, just a cautionary note to all that this comet, whilst the IAU predict mag -13.1, our team are estimating at around mag -8 to -9, and Daniel came up with -15.74 (which is the -16 quote being banded about), it could fizzle to nothing too. Nancy’s superb initial article was both fair and balanced (and we spoke about the images etc). Our team has papers published in Aphys journal and Icarus on comet analysis, we’er doing Afp value analysis on the dust probably later today (real science!), and over the coming months will build a picture of the likelyhood of this comet performing or not, but… Read more »
Kevin Heider
Member
September 28, 2012 3:47 PM

The -15.74 figure is what JPL Horizons “Sun-Observer-Target angle” (S-O-T) lists for 2013-Nov-28 19:03 UT when the comet is only 0.4843° from the Sun. I suspect forward scattering has a lot to do with the brief spike in brightness. Of course that close to the Sun, the comet will probably be lost in the sky glare for casual observers.

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