Saturday, August 24, 2013

Nova Delphini 2013 (N Del 2013) August 21, 2013

In spite of the nearly full moon, I was able to spot Nova Delphini 2013 with my Canon Rebel XT and 300mm lens. The new nova (redundant?) isn't blowing apart like a supernova, but stealing enough gas from its neighbor to temporarily flare up much brighter than normal (10,000x brighter in a matter of days). The star itself is a white dwarf normally too faint to see with even some pretty hefty equipment (approximately +17 magnitude). I took a series of images and stacked them for a total exposure time of about 1 minute.

nova delphini 2013
Stack of 79 light frames 1.3 sec each, 300mm, f/5.6, ISO 1600 (30 dark, 20 bias)
Judging by the known magnitude of nearby stars, I'd estimate it at about +5.6 (but then again I've never estimated the magnitude of a nova before).

I used a chart from the American Association of Variable Star Observers (AAVSO) to identify the magnitudes of several other stars in my image, then tried to place N Del 2013 on a spectrum between them. This process is described in more detail here.

As it so happens, my guess of 5.6 plots perfectly on the AAVSO light curve for N Del 2013. Indiana time is 4 hours behind UTC, and I took my photos at 10:30pm on August 21 - so that puts me smack dab in the middle of the green dots just after midnight UTC on August 22.

nova delphini 2013 light curve graph
Light curve for N Del 2013, data from www.aavso.org
My observation (red circle) added in Photoshop
n del 2013 with delphinus
A wider shot of Nova Delphini 2013 showing location relative to Delphinus
21 subs, 19 darks each at 75mm, f/4.5, 4 sec, ISO 1600
Check out the light pollution from the moon in this last image! On my camera's LCD screen I could barely make out Delphinus, but I'm glad it showed up in my image.

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