Astroblog: STEREO catches Comet C/2012 S1 ISON firing up.

Monday, November 18, 2013

STEREO catches Comet C/2012 S1 ISON firing up.


Comet C/2012 S1 ISON imaged in the STEREO satellites H2A instrument from 13 November to 14 November. 3 comets, Mercury and a variable star are labelled so you know where to look in the animation.Click to embiggen	19 Images stacked in ImageJ and assembled into an animation. You will need to click on the image to embiggen it, so that you can see ISON, Lovejoy and 2P/Enke clearly.

My Earth based ISON campaign is over, ISON is too deep in the twilight for me to see from Adelaide (despite trying very hard), and it is now below the lower limit of travel of the iTelescopes.

But STEREO still delivers. ISON is currently visible in the H2A instrument of STEREO, along with C/2013 R1 Lovejoy, 2P/Enke and 2013 V3 Nevski (there's also a variable star winking on and off).

What's more, you can see the moment ISON went into outburst. It's between 02:09 UT and 04:09 UT on the 14th, and it turns on quite abruptly (you will need to embiggen the animation to see it clearly). In the last few frames you can see ISON's tail whipping about.

An enlarged, inverted version of the above animation is to the left. Comet Al does a much better version where you can see the tail clearly.

Labels: 2P Encke, C/2012 S1 ISON, C/2013 R1, Comet Al, Stereo Satellite