With the sky being so nice tonight (and having a strong desire to think about something other the barbaric events in London) I decided to try and get a picture of the supernova in M51. So I rolled the roof off of my observatory and used the C-14/ST-10XME to shoot this unguided 60" exposure of M-51 at f/5.5: http://www.trilobyte.net/paw/temp/M51SN001.JPG That's a stretched version and the SN (arrowed) seems to show up pretty well. Looking at the raw image, however, showed me why we've been having so much trouble eyeballing it through a telescope. The SN is located right in the middle of a very dense and bright part of one of the spiral arms. It was only after stretching the image to tone down the background that the SN seems to be visible. I say "seems" as the on line image I found shows a fairly bright star right next to the SN so I guess the only way to tell if my suspect is the SN for sure will be to take another image in a few weeks after the SN has subsided. Patrick
I just shot another 60" image of M-51. As you might expect, with so little time between pictures there's no real difference (other than the seeing looks better tonight). However, it occured to me that I had shot M-51 before so I looked through the pictures on my web page and found one from 27 April 2000. http://www.trilobyte.net/paw/slas/patrickw/PATRICKW013.JPG While also taken with the C-14 this was taken at f/7 for 5 minutes using an SBIG ST-6B. I see nothing at the SN's location in that picture but I sure do in the one I took last night (see below). But (sorry Joe) I'm not seeing it in your picture (http://www.utahastronomy.com/Joeb/m51color). Opinions? Patrick Patrick Wiggins wrote:
With the sky being so nice tonight (and having a strong desire to think about something other the barbaric events in London) I decided to try and get a picture of the supernova in M51.
So I rolled the roof off of my observatory and used the C-14/ST-10XME to shoot this unguided 60" exposure of M-51 at f/5.5:
http://www.trilobyte.net/paw/temp/M51SN001.JPG
That's a stretched version and the SN (arrowed) seems to show up pretty well.
Looking at the raw image, however, showed me why we've been having so much trouble eyeballing it through a telescope. The SN is located right in the middle of a very dense and bright part of one of the spiral arms.
It was only after stretching the image to tone down the background that the SN seems to be visible.
I say "seems" as the on line image I found shows a fairly bright star right next to the SN so I guess the only way to tell if my suspect is the SN for sure will be to take another image in a few weeks after the SN has subsided.
Patrick
Hi Patrick,
However, it occured to me that I had shot M-51 before so I looked through the pictures on my web page and found one from 27 April 2000.
Did you "stretch" this 27 April 2000 image using the same processing steps that you used to reveal the SN on your more recent image? Does it even make sense to do so (in an attempt to make the backgrounds of comparable density), or would doing so be too much of an apples-to-oranges thing? Chris
cpclark@xmission.com wrote:
Hi Patrick,
However, it occured to me that I had shot M-51 before so I looked through the pictures on my web page and found one from 27 April 2000.
Did you "stretch" this 27 April 2000 image using the same processing steps that you used to reveal the SN on your more recent image?
Not to the same extent. But then manipulating the image wasn't really necessary to see the SN. Stretched or not it was visible, just more visible when stretched. However, just to be sure, (and if I remember to do it) I plan on shooting similar pictures in future. BTW, this morning's issue of News (went out about 5 minutes ago) carries a link to before and after pictures of M-51 and the SN. Patrick
This episode reminds us that if one is searching for supernova via imaging, dead-on tracking and precise focus are essential. Galaxies are not the largest nor brighest of targets, so typically the image scale is getting up there and the exposures are longish. Any fuzziness in the image just makes identification more difficult. These criteria apply to digital as well as emulsion imaging. Add precise registration for digital stacks. Paying attention to the details pays off. Consider that some of the most successful supernova finders of the 20th century used visual techniques only- they actually had the fields of dozens to hundreds of galaxies MEMORIZED. They did this for the sake of expediency. Their limiting magnitude was typically much lower than an imaged search, but they could examine a much larger number of targets in a given unit of time. To me, that is incredible dedication and a true demonstration of critical observing skill. C. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com
I think you're right, Patrick. The supernova apparently does not show up in my June 18 photo. What I believed was the SN in that view is just a star cloud. I couldn't tell the difference. But early Saturday morning I did take pictures that I believe show the supernova. I'll post them and one or two others in a short while. Best wishes, Joe
participants (4)
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Chuck Hards -
cpclark＠xmission.com -
Joe Bauman -
Patrick Wiggins