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 Post subject: Re: Comet ISON
PostPosted: Fri Nov 29, 2013 11:57 am 
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This was the image that prompted the news reports last night that Comet ISON was no more. The cross is where ISON should have been.


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 Post subject: Re: Comet ISON
PostPosted: Fri Nov 29, 2013 1:21 pm 
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I would guess that without a bright tail it would be very difficult to find in all that solar activity. On that scale you could probably fit several earths inside those prominences so finding a body less than a few kilometres in size would be pretty challenging.


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 Post subject: Re: Comet ISON
PostPosted: Fri Nov 29, 2013 2:35 pm 
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That red SDO image looks like it came from their AIA 304 camera, which uses a narrowband filter at 304 Angstroms and is tuned to pick up singly-ionised Helium (He II) at a temperature of around 50,000 degrees. So perhaps it's not surprising that it couldn't detect anything of the comet.
But looking at the latest LASCO C3 image from SOHO (from 09:22 this morning). ISON's coma has now grown very large (about half the diameter of the Sun) and it's developed a very wide fan-shaped tail. It's certainly worth looking out for just before sunrise (which is around 8am) if we get any clear skies over the next few days.


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 Post subject: Re: Comet ISON
PostPosted: Fri Nov 29, 2013 8:49 pm 
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Latest news from Sky and Telescope:

http://www.skyandtelescope.com/communit ... 09261.html

Looks brighter than Antares!


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 Post subject: Re: Comet ISON
PostPosted: Sat Nov 30, 2013 8:13 am 
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The latest LASCO C3 images show that the comet is fading rapidly as it recedes from the Sun.
I went out at 7:30 this morning to have a look, but whilst most of the sky was clear, there was a bank of low cloud over the SE horizon, so although the crescent Moon was clear, I couldn't see Saturn or Mercury, and certainly no comet. :(
Incidentally, I was observing from the promenade in Queen's Park: the very site where our predecessors had their observatory a century ago.


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 Post subject: Re: Comet ISON
PostPosted: Sat Nov 30, 2013 10:13 am 
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Ross

I had an identical experience this morning, got a few shots of the moon as consolation. I think that thin waning crescent moon is called "New moon in the arms of the old" and the other way around when it's a waxing crescent. Quite an eerie sight as it rises out of the gloom around the horizon. It's a shame if we don't get to see ISON after it's epic journey.

A more positive result is discovering the SOHO website (thanks Ross and Carl) which adds another dimension to observing. The LASCO 2 is displaying the following image at the moment, this coronal ejection has been going on for quite a few hours, I hope its not headed our way.

Attachment:
LASCO2CME.jpg


Regards

Bernie


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 Post subject: Re: Comet ISON - two more points of view!
PostPosted: Sat Nov 30, 2013 1:48 pm 
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And thanks to Bill Bones for providing this link to the image sequences from the twin STEREO spacecraft:
http://www.isoncampaign.org/karl/a-trail-of-questions
Perhaps we should ask Antony Jennings if he can make these into a 3D video?


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 Post subject: Re: Comet ISON
PostPosted: Sun Dec 01, 2013 10:15 am 
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Sadly it's already faded into a faint remnant, even whilst still within the LASCO C3 field, at midnight on 30-Nov:
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File comment: LASCO C3 image from SOHO spacecraft at 00:06UT on 1-Dec
isonremnant.jpg
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But at least Lovejoy's comet (C/2013 R1) is still visible - and easy to find, near to Beta Bootes. You may just catch it low in the NW after sunset, but it's best seen high in the NE in the early morning.


Last edited by rwilkinson on Tue Dec 03, 2013 6:42 am, edited 1 time in total.

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 Post subject: Re: Comet ISON
PostPosted: Sun Dec 01, 2013 1:05 pm 
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Gosh Ross that is just a smudge now.
Watching the videos, the solar flares looked to be the last straws - each one seemed to batter a bit more off it.

PS Well done Dave Walker for getting an image before perihelion - might be our only one and a collector's item.


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 Post subject: Re: Comet ISON
PostPosted: Mon Dec 02, 2013 9:25 pm 
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Spaceweather.com has posted this image from Stereo with an arrow to what is left of C. ISON - not much by the look of it. It says it was taken by an Italian but it clearly is a Stereo image.

http://spaceweathergallery.com/indiv_up ... gn6t88pmv1


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