Tuesday, June 28, 2011

Reprocessed Images and Something New

The recent lousy weather (for astronomy) has kept me indoors for some time now, and when that happens, I sometimes dig into the archives to see what I can reprocess.

Messier 27, the Dumbbell Nebula, was the first thing I imaged with the Epsilon-200. For some reason, I recorded all of the subs in JPEG format instead of CR2 (RAW). Regardless, I was very happy with the original image at the time. I've learned a few tricks for reducing noise, though, so I thought I'd take another stab at it:

Messier 27, the Dumbbell Nebula
For comparison, see my previous post of Messier 27.

I've never been very happy with my image of Messier 17, the Swan Nebula. Like my M27, I only collected JPEG images. The images were very noisy, which made it difficult to bring out the fainter details of the nebula without swamping the rest of the image in colored streaks. A program like Neat Image can be your friend in those circumstances.  Here is a redo of M17:

Messier 17, the Swan Nebula
And, finally, here is a "new" image of Messier 8, the Lagoon Nebula, that I imaged some time ago. I think this is the first time that I've posted it in a public forum:

Messier 8, the Lagoon Nebula; Epsilon-200 on NJP; 17x120

Saturday, June 11, 2011

Supernova 2011dh

On May 31, 2011, amateur astronomer Amédée Riou of France discovered a supernova in Messier 51, the Whirlpool Galaxy. It was independently discovered by other astronomers shortly afterward, and is currently being observed by professional and amateur astronomers world-wide.

Below is an image that I took of M51 on June 8, 2011. A first-quarter moon was up and the sky was hazy, so the detail isn't that great. The supernova, now designated SN 2011dh, is as bright as many of the foreground stars in this image. Considering that M51 is 23 million light years away, that's pretty bright!

SN 2011dh in M51; ST80 on Vixen SP; 14x180
For comparison, here is a shot of M51 that I took with the Epsilon-200 on April 24, 2010, reduced and rotated to approximately the same size and orientation as the image above.

Below is the full-size version of the Epsilon-200 image. The moon was about 85% full that night, but the sky was much clearer than the other night.

Messier 51, the Whirlpool Galaxy; Epsilon-200 on NJP; 25x120
SN 2011dh is expected to remain visible for the next few months. It has been determined to be a Type II supernova, which means that it was caused by giant star that collapsed in upon itself. The debris from this star will be scattered into interstellar space and may end up becoming the raw material for new stars and planets. The core of the star likely collapsed into either a neutron star or a black hole.

SN 2011dh is the third supernova observed in M51 in the past 17 years, which is a remarkably high frequency considering that our own galaxy averages only one supernova every 50 years!