Could somebody briefly explain what they mean when they refer to the ‘hydrogen bubble’ in this article - http://www.newscientist.com/article.ns?id=dn6942 - ?
“It’s huge. The Sun’s bubble is a tiny fraction of a light year across. This thing is dozens of light years across.” A tiny fraction of light year can still be pretty vast, so what is this bubble?
Is it the drifting away of hydrogen cause-it’s-so-damn-light, forming a far-reaching cloud around the star?
I expect this Wikipedia article on the heliopause will be of interest to you. The phenomenon is explained there better than I could.
(I’m not an astronomer, but I’m a layman who reads everything on the subject I can find.)
New Scientist wasn’t very clear on what the astronomers looked at were they?
The CSIRO press release isn’t much better, but at least it has a pretty picture. The abstract for Astrophysical Journal Letters continues the trend, and the paper itself (pdf from the abstract site) crashes my copy of Acrobat.
As Cervaise mentioned, they seem to be talking about the remnant of a heliosphere, carved out of interstellar gas clouds by the stellar wind from a massive star -before it went supernova. But there doesn’t seem to be any mention of the supernova remnant itself, which surely contained enough high velocity gas to obliterate the pre-existing heliosphere.
It’s kind of confusing. 
