Supernova in M51

The last few nights have been cloudy here in NM but it cleared out last night so I took a picture of Supernova SN 2011dh in M51, the Whirlpool Galaxy. The supernova was first detected on May 31st, so it was already a week old by the time I took this picture. M51 is about 37 million light years away and SN 2011dh is as bright as the foreground stars in our own galaxy. Now that's bright!

Last night's picture is a monochrome image taken with my NP101is 4" refractor and ST8300M camera using just an IR/UV blocking filter. It's a stack of thirteen 3-minute images for 39 minutes of total exposure. Since I had taken a color image of M51 a few months ago I made this composite picture showing the new and old images of M51 so they can be compared easily.

Rick Young
June 8, 2011