Comet ISON Options

[djellison]

Again - you're proposing an utter overhaul on not just the nuclei of comets, but the ground and space based observations of THIS comet - based on the fact that one instrument on one spacecraft didn't see one particular thing.

Moreover - we don't know for sure that SDO didn't see it. We've simply seen the uncalibrated browse data - not processed science products yet. It may well make its presence known in the SDO data yet.

[scalbers]

Still there in this STEREO-A view in the upper right

http://stereo-ssc.nascom.nasa.gov/browse/2...11801_s7h1A.jpg

Good discussion in this CBET telegram here:

http://groups.yahoo.com/neo/groups/comets-...ns/topics/22839

[TheAnt]

Good discussion in this CBET telegram here:

Thank you for that link. While it it for a while did look promising that at least some part of ISON had made it. It seem increasingly likely that what we did see where a 'ghost' with gas and particles - so Monty Python get a nod for his "Ain't Dead Yet" reference earlier - it appear to cover this most closely.

[titanicrivers]

And the most amazing animation of ISON's ashes being scattered in the solar wind was that of E Lakdawalla's Stereo B images in post #236
http://planetary.s3.amazonaws.com/assets/i...83900_dbc2B.gif

[scalbers]

This is the last frame I can see it in, after that it appears to have faded...

http://stereo-ssc.nascom.nasa.gov/browse/2...31801_s7h1A.jpg

Thus maybe December 2nd will end up being the last observation?

[CAP-Team]

What's the current status of ISON? Has Hubble or any other telescope viewed what is left of of ISON (if there is any)?

[MahFL]

Most of the consensus is ISON was destroyed by the Sun and what we saw fly away from the Sun briefly was the dusty debris.

[dvandorn]

I find it fascinating that the Science channel has been advertising a special called "Supercomet ISON" that will air this coming Saturday, IIRC. Even well past perihelion they were using the old ad copy saying it's 3 miles across and will soon be bright in our evening skies.

They are going ahead with the special program, but the ads now say (slightly paraphrased) "It's just gone around the sun -- but what happened then? Tune in and find out!"



-the other Doug

[0101Morpheus]

I'm sure the network paid for the program far in advance. It would be a shame to waste it now just because the comet no longer exists. Ahh, the power of advertising.

And hype.

[JRehling]

Hubble doesn't point near the Sun, so it was never an option for imaging ISON near perihelion. Hubble has never imaged Mercury and has only imaged Venus, AFAIK, once. This restriction is because of fears of damaging it. Other space telescopes are designed to observe nearer the Sun (or AT the Sun) and those produced many of the best observations of ISON.

[scalbers]

What's the current status of ISON? Has Hubble or any other telescope viewed what is left of of ISON (if there is any)?

Current status appears to be that it is visible in binoculars (December 6) to skilled observers, especially at high northern latitudes (where the geometry is best) like this report from Poland. It's apparently still a diffuse object about 15 arc minutes in diameter about 7.5 magnitude.

http://groups.yahoo.com/neo/groups/comets-...ns/topics/22913

A second observer visually saw it from Spain on December 7th at magnitude 7.2 (also on comets-ml). Interesting that there is skepticism about these sightings on the Sungrazer Twitter feed, where it's stated the comet should be 11th magnitude. Also a couple of negative results with images posted in Spaceweather.com.

Also, a nice STEREO animation from back on December 1 (by Alan Watson on comets-ml):

http://3.bp.blogspot.com/-u2oT6rAew8c/Up6C...son-hi1a-10.gif

And a still STEREO shot (Tony Scarmato - comets-ml) from December 4th:

https://fbcdn-sphotos-a-a.akamaihd.net/hpho...586950229_n.jpg

[Paolo]

the Hubble Space Telescope did not detect any debris from ISON, despite going as deep as the 25th magnitude
http://hubblesite.org/hubble_discoveries/c...n-is-still-dead

[scalbers]

It seems a lot of the Hubble and other recent "upper limits" may have been for the magnitude of a point object. It would give me a better feel for the overall ability to detect something if a magnitude per unit area was also considered. This corresponds to the surface brightness of an extended object.

This point is mentioned in comets-ml as well, here:

http://groups.yahoo.com/neo/groups/comets-...ns/topics/23004