Astroblog: Comet C/2012 S1 ISON, good tail action in STEREO (20 November, 2013)

Saturday, November 23, 2013

Comet C/2012 S1 ISON, good tail action in STEREO (20 November, 2013)


Comet C/2012 S1 ISON imaged in the STEREO satellites H2A instrument on 20 November to 14 November. 3 comets, Mercury and the Pleiades are labelled so you know where to look in the animation. 12 images stacked in ImageJ, aligned then the imges differenced to cancel out stars. Click to embiggen	12 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 and their tails at their best.

The latest images of comets ISON, Lovejoy and Enke in the STEREO H2A instrument. The data was processed using a difference macro in ImageJ which subtracts out non moving pixels to bring out more details with the comets. Enke and ISON have active tails, and I may have caught the edge of a tail disconnection event with ISON.

For comparison, here's the data from the 14th, reprocessed using Comet Al's difference macro to the same scale (the Pleiades is near the leftahnd edge and Mercury is just entering the field).

You can clearly see the active tail now, and the brightness jump when the out burst occurs is still readily seen.

ISON is very obviously brighter on the 20th, have to do some astrometry to determine how bright.

I have lots of images to download and process, this may take a while. But clearly the plotting of tail and brigness evolution is well worth it.

Labels: 2P Encke, C/2012 S1 ISON, Stereo Satellite