Author Topic: Comet ISON  (Read 10227 times)

Quialiss

  • Global Moderator
  • Sr. Member
  • *****
  • Posts: 494
    • View Profile
Re: Comet ISON
« Reply #30 on: November 28, 2013, 08:41:15 pm »
Just after the G+ hangout ended on a sad note of ISON being a no show in the SDO data, meaning it was likely vaporized before it got to that point...



IT'S ALIVE!  Not a very impressive alive, but it's come out the other side!  Stereo A actually has a much better view, as the nucleus never left the FOV of COR2/COR1, but beacon data being what it is it's been quite difficult to tell what's going on. 

Quialiss

  • Global Moderator
  • Sr. Member
  • *****
  • Posts: 494
    • View Profile
Re: Comet ISON
« Reply #31 on: November 28, 2013, 11:48:54 pm »
Despite it only being beacon data, I still think STEREO A has the best view of ISON:  The nucleus never goes behind an occluding disk, and we're seeing it almost perpendicular to the tail, meaning we see it in its full glory. 

Perihelion and post perihelion animation.  What it'll do next, nobody knows.  That tail it's sporting is GORGEOUS though, it has to be something like 30-40 degrees wide.  I am expecting great things from the science data, even if ISON fades to nothing on the next frame.  :) 



Also, I spot ISON coming out from behind the occluding disk on STEREO B COR1.  Hopefully this means that we'll see it in EUVI!  Who knows after it didn't show up on SDO at all. 

voyager1682002

  • Full Member
  • ***
  • Posts: 140
    • View Profile
Re: Comet ISON
« Reply #32 on: November 29, 2013, 08:41:35 am »
Great, it's still ALIVE!!  ;D

jules

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 1416
    • View Profile
Re: Comet ISON
« Reply #33 on: November 29, 2013, 12:19:51 pm »
Amazing stuff - it's a great ambassador for comets! I keep checking the Stereo / SOHO movies for latest developments too.

Latest LASCO C3
« Last Edit: November 29, 2013, 12:26:27 pm by jules »

Quialiss

  • Global Moderator
  • Sr. Member
  • *****
  • Posts: 494
    • View Profile
Re: Comet ISON
« Reply #34 on: November 29, 2013, 04:06:47 pm »
ISON has now left the STEREO A COR2 FOV... hanging on a little bit longer in STEREO B.  Tomorrow it should enter STEREO A HI1's FOV. 

Can't wait to see the first pictures from the ground.  STEREO and SOHO might win out when it comes to continuous observations near the sun, but I want to see what's in that overexposed coma!



--

Some 'old' data from Stereo, as science data gets uplinked.  There's still a little bit left from HI1B that we don't have science data on yet, and then of course the COR2/COR1 data from both spacecraft.  ISON was visible even on the beacon data at perihelion in COR1A, I can't wait to see it as more than a pixelated smudge. 

http://cometal-comets.blogspot.com.au/

(the videos)
https://docs.google.com/file/d/0B8nmkBCv3glJS0RHRmFmYTF1dHc/edit
https://docs.google.com/file/d/0B8nmkBCv3glJcXducEdJZUctUnc/edit


--

Science data treats

http://www.isoncampaign.org/files/images/blogpics/cor2a_anim.gif
http://www.isoncampaign.org/files/images/blogpics/cor2b_anim.gif

Still to come is the COR1 data from both craft, EUVI from STEREO B, and looking to the future, HI1 data from A and B.
« Last Edit: November 30, 2013, 02:25:26 pm by Quialiss »

jules

  • Global Moderator
  • Hero Member
  • *****
  • Posts: 1416
    • View Profile
Re: Comet ISON
« Reply #35 on: December 01, 2013, 12:01:02 pm »
It's now a shadow of its former self in STEREO A HI1. it did get our attention though!

Quialiss

  • Global Moderator
  • Sr. Member
  • *****
  • Posts: 494
    • View Profile
Re: Comet ISON
« Reply #36 on: December 03, 2013, 01:33:23 am »
Second last data we'll see of ISON, the last being from HI1A... and maybe a bit more depending on if it's decided that it's worth rolling either STEREO craft to continue observation. 

I find it rather fascinating that ISON fades completely from Ahead, despite the fact that we know that there's quite a significant tail still visible in the COR2 data at that time.  The disappearance of the tail in Behind is more understandable, the new tail is facing away from the sun, out of  the FOV of COR1.  Background subtraction on Ahead is also a little seizure inducing, I'm not sure why, the Ahead data isn't  that much messier than Behind.  It doesn't effect the comet viewing, though!


gwnashjr

  • Newbie
  • *
  • Posts: 29
    • View Profile
Re: Comet ISON
« Reply #37 on: December 03, 2013, 10:14:25 am »
ISON was indeed sporting a great tail.  I am curious though.  I know that the tail has an ion trail and a dust trail that I learned from the Google + NASA hangout but which is which in these videos.  Thanks!

Quialiss

  • Global Moderator
  • Sr. Member
  • *****
  • Posts: 494
    • View Profile
Re: Comet ISON
« Reply #38 on: December 04, 2013, 02:58:13 am »
I'm fairly certain it's the dust tail.  ISON never had a terribly spectacular ion tail, while it did have two separate dust tails on its last approach.

gwnashjr

  • Newbie
  • *
  • Posts: 29
    • View Profile
Re: Comet ISON
« Reply #39 on: December 08, 2013, 01:48:21 am »
Spectacular, thanks!

Quialiss

  • Global Moderator
  • Sr. Member
  • *****
  • Posts: 494
    • View Profile
Re: Comet ISON
« Reply #40 on: December 14, 2013, 06:20:28 am »
Last update for STEREO observations of ISON, the followup observations have been canceled, most likely due to the fact that the remnants of ISON are too faint to be detected by HI1. 

Quote
Week 50 (Dec 9-15)

* Simultaneous 30 degree rolls of Ahead, and 290 degree rolls of Behind, to
  observe Comet ISON, were carried out Monday and Tuesday (Dec. 9-10) with
  another scheduled for Wednesday, Dec 11 at 02:00 UT. These will be
  the final Comet ISON rolls.
( http://stereo-ssc.nascom.nasa.gov/minutes/weekly_20131210.txt )

My current understanding is that there is a planned observation attempt with Hubble in late December, as soon as ISON gets far enough away from the sun to safely point Hubble at it.. but the problem is 'just where are we pointing Hubble?'  The STEREO observations are the latest updated position for ISON, and hopefully there is enough data to correctly position Hubble to take a look at the remnants, but it's more of a guessing game than normal.