Thursday, 23 January 2014

A (supernova a) long time ago in a galaxy far far away...

A long time ago in a galaxy far far away, well about 12 million years ago and 1.135×1020 km to be precise, a star exploded. It exploded with such force that here, on Earth, all that time later the photons are arriving, and we can see them...

I'm talking about the supernova that was detected in M82 (the cigar galaxy) just yesterday, with the catchy temporary name PSN J09554214+6940260 (now called SN 2014J). Supernovae are enormous explosions. It is really hard to get your head around how big they are. To quote XKCD:

Which is brighter?
     1) A supernova, seen from as far away as the Sun is from the Earth, or
     2) The detonation of a hydrogen bomb pressed against your eyeball?

The answer is 1. By a factor of a billion. The sheer amount of energy supernovae release is simply unimaginable. They are also rare, the last supernova to happen closer to Earth than this one was in 1987. Right now is a great and rare chance to try and see the spectacular swan song of a dying star!

Nine months ago I set myself the challenge of imaging the moons of Jupiter with just my standard digital SLR camera, and succeeded. Taking a picture of PSN J09554214+6940260, which is currently at around magnitude 11.5, seemed like a proper challenge!

To really know what we are looking at take a look at this picture which I took of M82 in April last year:


M82 is the smudgy line below and left of the M82 label. Now lets see what M82 looked like tonight (22nd January):



Let's look a bit closer:

April 2013

22nd January 2014

It's faint, it's noisy, but there certainly seems to be an extra star right on M82, exactly where the supernova is positioned... Is that slight spot really the supernova? The forecast is that the supernova will get brighter over the next week or so, so (if there are no clouds) I can take more photos and confirm it!

It is crazy to imagine the journey the few photons that my camera picked up to make this picture have been through. Created 18 million years ago in one of the most violent explosions in the universe they have travelled 1.135×1020 km at the speed of light to reach Earth. They flew down through the atmosphere, into the lenses of my camera, then impacted onto the camera sensor. These photons' deaths, after their 18 million year lives, excited a few electrons, which were then detected and used to make this picture. Pretty epic.

Software used:
ImageJ: Image processing

The geeky details:
Canon EOS 450D
Sigma 18-200mm f/3.5-6.3 DC OS HSM
The lens was used at 200mm, maximum aperture (f/6.3), with focus set manually to infinity. 20 images were captured at ISO 800 with a 2.5 exposure time then aligned and averaged in ImageJ.

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