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Do supernovae in other galaxies look like this?


Piero

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I was looking at this amazing full resolution image of M81 (hh121-2007-19.jpg ; 74.5MB) made by HST and casually looked at the surrounding space until a galaxy in a corner attracted my attention. :rolleyes: 

The galaxy in question is circled in this photo at lower resolution (hh121-2007-19-1920.jpg ; 293.3 KB): 

hh121-2007-19-1920__edited.jpg

 

 

I cropped the area in the above circle from the full resolution image. This is shown below.

hh121-2007-19__cut.jpg

 

 

Do you think that that bright red dot on the galaxy branch to the top left of the core is a supernova? :help:  

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SN Reporting.jpg

May be difficult to read, but Interesting if you can. We all feel like gaining Immortality finding a SN.
Many have of course. The difficulty is assuring oneself that the evidence is strong enough to report.
I'd love it if you are right.

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The full resolution image is very impressive, you can see background galaxies peeking through the arms of M81. Here's a direct link to the page, I had to download the file to view it as at 22620 X 15200 as it was crashing my browser.

I'm fairly confident it's a foreground star I'm afraid, there is another with a very similar appearance down and to the right. By the way, what I said about red-shift in the previous post may not be accurate, as UV light would be shifted down to blue.

This thread has a few links that can be helpful for identifying galaxies, and Martin Meredith's Pretty Deep Maps may have it. If you can find a designation for the galaxy it should be possible to search for any supernova in it. Hope that's some help.

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29 minutes ago, Knight of Clear Skies said:

The full resolution image is very impressive, you can see background galaxies peeking through the arms of M81.

Bigger fleas have little fleas,

Upon their back to bite 'em,

Little fleas have smaller fleas,

And so ad infinitum.

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1 hour ago, Knight of Clear Skies said:

The full resolution image is very impressive, you can see background galaxies peeking through the arms of M81. Here's a direct link to the page, I had to download the file to view it as at 22620 X 15200 as it was crashing my browser.

I'm fairly confident it's a foreground star I'm afraid, there is another with a very similar appearance down and to the right. By the way, what I said about red-shift in the previous post may not be accurate, as UV light would be shifted down to blue.

This thread has a few links that can be helpful for identifying galaxies, and Martin Meredith's Pretty Deep Maps may have it. If you can find a designation for the galaxy it should be possible to search for any supernova in it. Hope that's some help.

Thanks for the info! Very interesting links. I forgot about Martin's maps. Worth checking on those too. 

Anyway no need to be afraid! :) Mine was just a curiousity. I don't know anything about imaging and for sure I was not pretending to have discovered a SN! It's nice to have a chat to learn more though! :) 

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Actually I think there is a possibility this is a dust reddened supernova. There is no sign of it on the SDSS or PanSTARRS  images of this region, where it just looks like a normal galaxy,  although admittedly the ground-based resolution isn't really good enough to be certain.

NigelM

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18 hours ago, Piero said:

If / when you have a chance, could you post the SDSS or PanSTARRS images that you considered for this comparison, please? I would be very curious!

Just go to http://skyserver.sdss.org/dr13/en/tools/chart/navi.aspx

and put in M81 as the name. You can then scroll around to find your galaxy (it is off to the top right somewhere). It isn't an SDSS detection as I suspect it is too near to M81. The Pan-STARRS images are not yet publicly released, so I will pass on that for now.

NIgelM

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This is the SDSS image rotated to match the excerpt from the Hubble image and sharpened beyond belief and then contrast enhanced until it squeals.

temp.jpg

To my mind there is a second bright patch up and to the right of the galactic core, but this image is FULL of artefacts..

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22 hours ago, Stub Mandrel said:

To my mind there is a second bright patch up and to the right of the galactic core, but this image is FULL of artefacts..

Beware - the SDSS navigator shots are jpg images with compression. One really needs to go back to the raw pixels. So here are the Pan-STARRS pixels (you have to forget you have seen them!). On careful inspection it is possible that there might be some evidence of the "star" being present (this would be taken several years after the HST shot I think, so if it is present it is not a supernova), but the seeing isn't quite good enough to be sure. Probably needs a bit of profile modelling (or someone could try blurring the HST shot to about 1" seeing)!

ps1_m81_gal_iband.jpg

p.s. the pixel size is 0.25"

NigelM

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