C/2012 S1 (ison) Could Be The Brightest Comet Ever Seen By Mankind

[mike Meehan]

Looks intact to me! or am i seeing something else?

 

Should be another day or two by the time it rounds the sun, so it's not out of the fire yet.

[Flipflop]

NASA live, talking about ISON.

 

NASA will host a media teleconference 6pm our time to discuss Comet ISON’s journey through our solar system and what the public worldwide may see in the coming days as the comet traverses the sun on Thanksgiving Day.

 

http://www.ustream.tv/channel/nasa-news-audio

Edited November 26, 2013 by Raptor Raw

[swebby]

Looks intact to me! or am i seeing something else?

 

From looking at the thread you posted the link to at the top of the page - It will appear as a comet for a few days even if the nucleus has disintegrated.  The failure to brighten any further and the lack certain emission lines in it's spectra is what appears to have some observers worried.

[Polar Maritime]

IS COMET ISON IN TROUBLE? Astronomers using the IRAM millimeter telescope in Spain are reporting a sharp change in Comet ISON. "We observe consistent, rapid fading of the molecular emission lines between Nov. 21 and Nov. 25 by at least a factor of 20. This may indicate that the nucleus is now at best marginally active or that... it no longer exists," says Michal Drahus of Caltech.

It's too soon to panic, though. First, click on the image to watch a movie from NASA's STEREO-A spacecraft (31 MB), then scroll down for continued discussion:

Credits: This movie was made by reader Rob Matson using data from STEREO-A.

The movie spans a 3+ day interval from Nov. 21 (00:09 UT) to Nov. 24 (08:09 UT), which overlaps the period when IRAM recorded the fading emission lines. Zoom your movie-player to full screen: Although "puffs" of material can be seen billowing down the comet's tail, the comet itself still appears to be intact.

Astronomer Karl Battams of NASA's Comet ISON Observing Campaign comments: "[The fading emission lines] could indicate that the nucleus has completely disrupted, releasing an enormous volume of dust while significantly reducing emission rates. Fragmentation or disruption of the nucleus has always been the highest risk factor for this comet so if this has indeed happened then while unfortunate, it would not be a surprise."

"However," he continues, "these reports are new, and while they are undoubtedly valid, we do still need to keep observing the comet to be sure what it happening. Remember: Comet ISON is a dynamically new sungrazing comet, fresh in from the Oort Cloud, and the last time we saw an object like this was never! Furthermore, a sungrazing comet just three days from perihelion has never been studied in this kind of detail - we're breaking new ground! When we factor in your standard 'comets are unpredictable' disclaimer, what we have is a huge recipe for the unknown." http://www.spaceweather.com/

[Bobby]

Whatever happens to the comet it will be interesting scientifically and a lot will be learnt. Is looking a bit worrying now regarding its survival as it rounds the Sun, if the reports are true then it would seem unlikely it will stay intact and could dissapear completely. If it does fragment it could still put on an impressive visual show, perhaps more so than if it stayed together. So one way or the other it's going to be fascinating to see what happens over the next few days.

Edited November 26, 2013 by Bobby

[Polar Maritime]

http://www.youtube.com/watch?v=2bbHRPKVecE

Edited November 27, 2013 by Polar Maritime

[Coast]

This one is nice and simple for a complete amateur like me!

 

 

http://www.theguardian.com/science/2013/nov/25/comet-ison-astronomy-uk-sun-stargazing-christmas-december

[Flipflop]

ISON steaming towards the Sun this morning and looks like it may miss the CME,just..

 

http://sohowww.nascom.nasa.gov/data/realtime-images.html

 

[Flipflop]

On November 28, 2013, the SDO (Solar Dynamics Observatory) spacecraft will off-point at three different positions as Comet ISON moves through perihelion. This website will display near realtime images and movies of this sungrazing comet. Images should begin appearing sometime between 12:45 pm and 1:00 pm ET.

 

http://cometison.gsfc.nasa.gov/

Edited November 27, 2013 by Raptor Raw

[Gray-Wolf]

http://www.space.com/23752-best-yet-comet-ison-footage-from-stereo-released-video.html

 

Sure gets bright in the last few frames!!!

[Bobby]

A lot of experts seem to think the comet is in trouble, has either become inactive due loss of volatile compouds or has fragmented or dissapeared altogether.

 

 

(1) On November 25.27 Michael Drahus a radio astronomer from Caltech/NRAO working with the IRAM millimeter radio telescope in Spain, and Israel Hermelo of IRAM/Granada, reported that there had been a consistent rapid fading of the molecular emission of this comet between November 21st and November 25th by at least a factor of 20 or even more. What is preocupating about this report is that molecular emissions measure the intantaneous activity of the comet, in contrast with visual observations were the cloud of debris can last for days around the nucleus thus masking any fragmentation.   Radio observations can be made during day or night and are not affected by the solar glare.(2)  Measurements of production rates and dust from the Trappist telescope in Chile on November 23rd, also show a decrease in activity by a factor of 3, according to Emmanuel Ejehin.(3) Nicolar Biver reports that astrometric observations were showing the comet trailing behind the ephemeris. This could happen if there is a cloud of debris lagging behind  the nucleus.  The nucleus may be non-existent and there would be no way of knowing. The offset is about 5 arc second, which at the distance of the comet is about 3000 km.(4) The non-gravitational forces are a measure of how much material is being ejected from the nucleus.  For a long period of time it was not possible to measure the non-gravitational forces. Now they have been measured and the value is larger than for comet LINEAR, a comet that disintegrated, by a factor of x1.1.(6) Our own results confirm that comet ISON may be in trouble.  We have completed an update of the Secular Visual Light Curve and we are showing it in the Figure 1.  This update includes spacecraft measurements.

 

The brightness has begun to increase again, but it is following a R^(-2) law characteristic of a reflecting body.  This suggests that comet ISON has stopped releasing volatiles.   Two people are making measurements of spacecraft observation, STEREO HI-1A.  They are Man To and M. Knight.  The measurements by Man TO required of a correction of -0.9  magnitudes to bring them to the level of the visual observations.  The measurements of Knight required of a correction of -0.75 magnitudes.   The new Visual Secular Light Curve shows that the comet is once again increasing in brightness but it is following a R(-2) law characteristic of a reflecting body.  This is the law followed by all asteroids.  This implies that comet ISON has stopped releasing volatiles and it is simply reflecting the solar light as an atmosphereless body.  This would be the case if there were a cloud of dust and debris.  However we still lack visual confirmation of the fragmention.   Spacecraft measurement must continue.  If the comet continues exhibiting the R(-2) law, it would be direct proof that it has stopped sublimating volatile and that it is really defunct.

 

 

http://astronomia.udea.edu.co/cometspage/ISCOMETISONINTROUBLE.xhtml

 

Nobody seems to know for sure what is happening but should be confirmed one way or the other over the next few days.

 

[Boro Snow]

• looking good with less than 24 hours to go
•  
• 

[Gray-Wolf]

Well we can all sit and watch it over at the Nasa solar site, hour by hour , blow by blow! As I said in my last post it sure looks a lot brighter in the last few frames of that movie but the latest ( 14.30) image shows it still there with quite a bright tail ( tapered off at the end?).

 

I'll certainly be watching it today and tomorrow and if it looks like it survived then I'll get ready for some early morning views!

[DAVID SNOW]

"Forward shields buckling Captain"

 

"Scotty I must have more power!" 

[Bobby]

Well we can all sit and watch it over at the Nasa solar site, hour by hour , blow by blow! As I said in my last post it sure looks a lot brighter in the last few frames of that movie but the latest ( 14.30) image shows it still there with quite a bright tail ( tapered off at the end?).

 

I'll certainly be watching it today and tomorrow and if it looks like it survived then I'll get ready for some early morning views!

 

According to some of the recent observations what we could be seeing is not a comet as such but a cloud of dust and gas and fragmented material from an ex-comet, going at the same speed and direction as a comet and hard to tell apart. Am no expert though.... shall just have to see what further observations reveal. Tomorrow should be interesting.

[Gray-Wolf]

http://www.ibtimes.co.uk/articles/525612/20131127/comet-ison-century-history-solar-system-particles.htm?

 

so now they tell us NASA is gearing up for the 'meteor showers' they expect from Ison's debris field??? The last we heard it was only 'dust' and could spark noctilucent displays as it settles into the Strat ( Jan 12th and the following week) but now they've geared up the U2 to collect leftovers from the shower???

 

I'd go for a good shower over Noctilucents any day ( both please!!!).

[Laurie61]

"Forward shields buckling Captain"

 

"Scotty I must have more power!" 

 

I'm givin you all she's got captain, She'l no take any more..! 

[Methuselah]

I'm givin you all she's got captain, She'l no take any more..! 

The di-lithium crystals are aboot tae blaw!

[mike Meehan]

"Forward shields buckling Captain"

 

"Scotty I must have more power!" 

How many more times must I tell you Captain, steer well clear of the black holes until we get this problem solved.

[Boro Snow]

https://mtc.cdn.vine.co/r/videos/7D46A968-72C9-4B34-84F3-D7366EB7913D-242-000000B1435433D8_1737621a627.0.7.mp4?versionId=GhXnN21XZAJBUUOF70LSTDvXrDdB3cmD

[Polar Maritime]

Updated image by LASCO C3 showing a much brighter Comet ISON as it continues to travel closer to the sun. The comet remains intact.

 

 

[Weather-history]

12 hours to go,

Speed now 386,400 mph and rapidly increasing.

[Polar Maritime]

12 hours to go,Speed now 386,400 mph and rapidly increasing.

 

Yes WH, and an important 12 hours at that ! Fingers crossed... 

[Coast]

Fingers crossed... 

 

+1

 

Ison: Critical time for ‘comet of the century’

 

Astronomers are anxiously waiting to see if a comet survives its encounter with the Sun. Comet Ison will reach its closest approach to our star at approximately 1835 GMT on Thursday. It has been billed as a potential "comet of the century", but the Sun's heat and gravitational tug could destroy it before it has a chance to light up the skies. Some scientists believe it is already starting to buckle under the onslaught.

 

Prof Tim O'Brien, associate director of the UK's Jodrell Bank Observatory, said: "It's like throwing a snowball into fire: it's going to be tough for it to survive. "But luckily, it's a big object and it moves fast, so it won't spend too much time close to the Sun. There is a lot of uncertainty." Comet Ison came from the Oort Cloud, an mysterious, icy region at the furthest reaches of our Solar System. It has been hurtling towards the Earth, travelling at more than a million kilometres an hour.

 

Now it is entering the most perilous stage of its epic journey. It will pass the Sun at a distance of just 1.2 million km, effectively grazing its surface. Professor Mark Bailey, from Armagh Observatory in Northern Ireland, said: "It's going to be exposed to the worst that the Sun can throw at it. "It will be getting exposed to more and more intense solar heat, and that will start to sublimate the ices (turning them into gas) at an increasing rate." The Sun's intense gravitational field produces tidal forces that will also have a major effect on the comet.

 

Scientists fear it could follow the path of Comet Lovejoy, which broke apart after it passed near the Sun in 2011. Or it could run out of fuel and fizzle out. Hopefully, Ison's large size could protect it. Astronomers estimate that its nucleus could be several kilometres in diameter, helping it to withstand the solar assault. If it does remain largely intact, the heat from the Sun will excite the dust and gas in its core, allowing it to blaze a trail across the night skies. But whether it really will be a "comet of the century" is unclear.

 

"If it survives, the best chance of seeing it will be in early December," explained Dr Robert Massey from the Royal Astronomical Society. "I very much doubt Ison is going to be the sort of object where you go out in the morning, just before sunrise, and see this amazingly spectacular thing across the night sky.

 

"It's much more likely, at the optimistic end, that it's visible with the naked eye, and with binoculars - you could see the comet's head and a nice long tail coming from that." There has been some debate already about whether Ison is starting to break up, and telescopes such as the Esa/Nasa Soho Sun-observing satellite will be trained on the star during the approach. "There is a lot of uncertainty, but it's going to be exciting to watch," added Prof O'Brien.

 

 

 

http://www.bbc.co.uk/news/science-environment-25129711

[Boro Snow]

Well the day is here is ISON going to survive thats the big question and one which many scientists cannot agree on, 6.45pm is it closest point to the sun  if i remember correctly, should be a fascinating day and one im really looking forward, i expect this thread to become really bizy later on today, also a link below which i think has already been posted in here a few pages back from NASA which starts streaming from 5.45pm ish,

 

Lets hope she survives and we do get the brightest comet in mankinds History, happy viewing guys 

 

http://cometison.gsfc.nasa.gov/

Edited November 28, 2013 by Boro Snow