How to See Comet ISON This Week -- Nov. 18-24

[Buster's Uncle]

How to See Comet ISON This Week -- Nov. 18-24
David J. Eicher. Editor-in-Chief, Astronomy magazine  Posted: 11/20/2013 11:41 am



By mid-November, the much-anticipated Comet ISON (C/2012 S1) really began to put on a show. Lagging slightly behind the predicted magnitudes, it experienced an outburst and brightened by a factor of 10 in one day. The comet is now a naked-eye object, visible in twilight in the early morning sky, but with the Moon also hampering the view.

ISON will swoop quite close to the Sun on November 28, some 1.8 million kilometers from our star's surface, which will enable it to light up dramatically.

This gorgeous photo shows the way the appearance of the comet on November 15:



Credit: Damian Peach


To see it this week, you'll need to venture out in the early morning, between 4 a.m. local time and dawn, and look to the southeast, toward the constellation Virgo. Because moonlight makes seeing sky objects harder, you may need a pair of binoculars to pick it up, although the comet now glows at around 4th magnitude, well within the range of being visible with the eye alone.

At midweek, the comet rises 1 hour 50 minutes before the Sun and is positioned south of the bright star Spica, the brightest luminary in Virgo. Nearby lie both the planets Saturn and Mercury, and the comet's motion is of course carrying it rapidly toward the Sun.

This map will show you exactly where to look:



Credit: Astronomy: Richard Talcott and Roen Kelly


In late November, Comet ISON moves its fastest as it flies from Virgo, through Libra and Scorpius, and then heads north into Ophiuchus.

Other comets are visible in the morning sky, too, including the relatively bright Comet Lovejoy (C/2013 R1), which is heading northeastward into Leo Minor, and a famous periodic comet, 2P/Encke, which is very low in the twilight.

Comet ISON will appear as a soft glow, a fuzzball shimmering from the gases released from the comet's frozen nucleus, which measures perhaps two kilometers across, as it increasingly warms in sunlight. The comet's so-called coma, the fuzzy blob you'll see in binoculars or a telescope, spans about 5 arcminutes across. That's one-sixth of the diameter of the Moon. A faint tail drifts away some 0.3°, more than a third of the Moon's diameter, and will be slowly growing over the coming days.

Over the weekend I attended the Arizona Science and Astronomy Expo in Tucson and took part in a comet panel discussion with astronomers David Levy, Steve Larson, Jim Scotti, and Carl Hergenrother -- all comet discoverers. The feeling is that the comet may continue to outburst as fresh ices are exposed to sunlight, which could lead to more dramatic brightening. The comet's tail is already showing several discrete streamers, producing beautiful and elegant images. And the comet has shown a small arc-shaped feature near the inner coma that may be indicative of some fragmenting of the nucleus. This doesn't necessarily mean it will break apart, but rather that areas of different density are warming at different rates and streaming away from the nucleus.

Over the next week, ISON should continue brightening significantly. Keep your eye on the comet and realize that, even if it's subtle, you're witnessing one of nature's most amazing visitations, a rare and distant traveler wafting into the inner solar system, a stranger from the sea of darkness beyond us.


http://www.huffingtonpost.com/david-j-eicher/how-to-see-comet-ison-thi_3_b_4309366.html?ncid=txtlnkusaolp00000592

[Geo]

I had a chance two mornings ago (clear skies to the east), but couldn't spot it.
Now it's semi-permanently overcast. We even had a little snow last night.

[Buster's Uncle]

Promising Comet ISON Gets Brighter, But Will It Really Sizzle?
SPACE.com
By Joe Rao, SPACE.com Skywatching Columnist  22 hours ago



Comet ISON's position in December 2013 is shown on this sky map.



Many skywatchers tracking Comet ISON don't want to get their hopes up about the recent brightening of the possible "comet of the century."

The comet appeared to be floundering, brightening at a disappointingly slow pace as recently as Nov. 12. That day — based on a consensus of observations worldwide — Comet ISON was shining at magnitude 7.9, or more than 3.5 times dimmer than the faintest star visible to the eye without optical aid.

Then suddenly and unexpectedly, the comet brightened. Starting at 7 p.m. EST (0000 UTC) on Nov. 14, the comet's outburst began, and its brightness quickly jumped to magnitude 5.9. By the following day, it had soared to magnitude 5.1 — a more than 13-fold increase in brightness in less than three-days.

But while the comet's rapid increase in brightness was initially treated as good news, observers now fear that ISON's outburst could signal its demise. There has always been talk that ISON might prematurely break up or disintegrate before it whips to within 730,000 miles (1,175,000 km) of the sun on Nov. 28.

If the comet were to suddenly disintegrate into a cloud of dust around that time it probably would unfurl a long and spectacular tail similar to the one that appeared in December 2011 after Comet Lovejoy's close brush with the sun.

However, if that break-up and disintegration process were to occur many days before perihelion (the comet's closest approach to the sun), then after an initial flare-up in brightness, the comet would begin to gradually fade, eventually becoming lost to view in the glare of the sun, never to be seen again.  Such was the fate of Comet du Toit, a sungrazing comet in December 1945.



Comet ISON shows off its tail in this spectacular space wallpaper taken on Nov. 19, 2013


David Seargent, a well-known Australian comet observer, noted on Saturday (Nov. 16) that Comet ISON was similar to the distance at which Comet du Toitwas observed.

"At the time, this comet was intrinsically brighter than Comet Lovejoy at a similar distance, du Toit apparently faded out prior to perihelion," Seargent said. "Time will tell whether the ISON outburst was also cataclysmic or something less destructive."

Astronomer Zdenek Sekanina at NASA's Jet Propulsion Laboratory echoed similar feelings last week: "It is unclear whether this event's nature is benign or cataclysmic."

It's also possible that the sudden brightening of ISON might actually be good news. As the comet continues to be exposed to the increasing light and heat of the sun, a new fissure has possibly opened on the comet's nucleus, which in turn is now expelling a new reservoir of gas and dust.

But at the present nobody can say for sure. Skywatchers will just have to continue monitoring the comet in the days to come as it presses closer to the sun.

Currently about magnitude 5, ISON should be no problem to see. It is dimly visible to the unaided eye, even under the light of the nearly full moon. Some have even reported spotting a faint tail.

Early today (Nov. 20), ISON was positioned roughly between the bright star Spica and the planet Mercury. From here on out, however, it will get harder to see ISON. The comet is now descending into the ever-brightening glow of the rising sun, and after Friday (Nov. 22) the comet will be all but out of sight — hidden by low altitude and the bright dawn twilight.

After that, observers will have to wait about a week until the comet finally skirts the sun's surface. Will the comet survive its close brush with the sun, or will it fizzle? At this point, stargazers will just have to wait and see.

You can follow the latest Comet ISON news, photos and video on SPACE.com.


http://news.yahoo.com/promising-comet-ison-gets-brighter-really-sizzle-231350373.html

[Geo]

 

[Buster's Uncle]

NASA Sees Comet ISON 9 Days Before Close Sun Encounter
SPACE.com
By Tariq Malik, Managing Editor  6 hours ago



Comet ISON shows off its tail in this three-minute exposure taken on Nov. 19, 2013 at 6:10 a.m. EST



NASA astronomers have captured an amazing new photo of the brightening Comet ISON, an image that reveals the comet's intricate tail as it heads for a rendezvous with the sun next week.

The new photo of Comet ISON was taken Tuesday (Nov. 19) by scientists at NASA's Marshall Space Flight Center in Huntsville, Ala., nine days ahead of the comet's Thanksgiving Day close encounter with the sun on Nov. 28.

"Comet ISON shows off its tail …" NASA's image description begins. The comet photo was taken early Tuesday at 6:10 a.m. EST (1110 GMT) by Aaron Kingery at the Marshall center. He used a 14-inch telescope with a three-minute exposure time, according to the image description.]

"The comet is just nine days away from its close encounter with the sun; hopefully it will survive to put on a nice show during the first week of December," NASA officials wrote of the image. "The star images are trailed because the telescope is tracking on the comet, which is now exhibiting obvious motion with respect to the background stars over a period of minutes."

Comet ISON was first discovered by Russian amateur astronomers Vitali Nevski and Artyom Novichonok in September 2012 with a remotely operated telescope in the International Scientific Optical Network (ISON). The comet is officially designated as C/2012 S1 (ISON).

On Nov. 28, Comet ISON will make its closest approach to the sun and come within 730,000 miles (1.2 million kilometers) of the solar surface. The comet has drawn much attention from the public, stargazers and professional astronomers because of hopes that it might flare up into a so-called "comet of the century" after its sun flyby.



Where to look for Comet ISON low in early dawn on the morning of November 22nd


While Comet ISON did not brighten as predicted, the comet did undergo a surprise outburst last week to become visible to the naked eye in the southeastern pre-dawn sky. The comet is more clearly visible in binoculars and telescopes, and can be found low in the the east-southeastern sky about one hour before sunrise.

The major uncertainty with Comet ISON is whether it will survive its encounter with the sun, or if it will break apart and be destroyed. Scientists aren't yet sure which path the comet's evolution will take.


http://news.yahoo.com/nasa-sees-comet-ison-9-days-close-sun-171853621.html