Being able to tell subtypes of Type IA supernovas

Was the Type Ia SNe caused by a white dwarf-white dwarf collision or a
white dwarf-gaseous star collision?

Yousuf Khan

Astronomers pin down origins of 'mile markers' for expansion of universe
| e! Science News
http://esciencenews.com/articles/201...io n.universe

Thanks Yousuf!
From
http://esciencenews.com/articles/201...io n.universe


The Ohio State astronomers found their answer in the light spectrum emanating from the supernova. If the companion were a star like ours, or even a giant star, a sizeable portion of the debris blown away from the supernova would contain atoms of the element hydrogen.

Supernova 2011fe provided a good chance for the researchers to test for the presence of hydrogen. Located in the Pinwheel Galaxy some 21 million light-years away, it was the closest near-Earth Type Ia supernova to occur in the last 20 years.

"If the companion were a star such as ours or even a red giant, we would expect to see a lot of hydrogen in the signal -- maybe even half a solar mass' worth, as the companion was blown away. But instead, we saw at most only one tenth of one percent of a solar mass' worth of hydrogen. That suggests that the white dwarf's companion had very little if any hydrogen in it, and is likely another white dwarf," Shappee said.

On Friday, November 23, 2012 4:41:31 PM UTC-8, Yousuf Khan wrote:
Was the Type Ia SNe caused by a white dwarf-white dwarf collision or a

white dwarf-gaseous star collision?



Yousuf Khan



Astronomers pin down origins of 'mile markers' for expansion of universe

| e! Science News

http://esciencenews.com/articles/201...io n.universe

http://sphotos-a.xx.fbcdn.net/hphoto...50673577_n.jpg

On Friday, November 23, 2012 4:41:31 PM UTC-8, Yousuf Khan wrote:
Was the Type Ia SNe caused by a white dwarf-white dwarf collision or a

white dwarf-gaseous star collision?



Yousuf Khan



Astronomers pin down origins of 'mile markers' for expansion of universe

| e! Science News

http://esciencenews.com/articles/201...io n.universe

The thing that bothers me here is that the author only refers to the parent galaxy as "The Pinwheel", and that is about as unscientific as you can get, in my view. There are at least (3) well-known galaxies with this designation, those being M33, M101 and M83, and there are undoubtedly more. In this case, the supernova was in M101, which also carries the designations NGC 5457, UGC 8981, PGC 50063, and Arp 26, and there are a couple of dozen more..

This lack of attention to a simple detail makes me wonder about the rest of the article. Just sayin'.

\Paul A