bija 0 Report post Posted October 2, 2008 Many more stars are being created around the Universe than was thought, surprised astronomers reported. Optical telescopes can rarely be used to see the birth of stars in deep space, as the distances are too great. Instead astronomers look for a form of radiation, called H-alpha emissions, which flare when a big star bursts into life from a compressed ball of gas. The H-alpha telltale only occurs around the vicinity of very heavy stars, not light ones. Light stars are far more plentiful but do not have a mass big enough to emit the rays. So, to get a rough estimate of light stars, sky-watchers have used a yardstick that 230 light stars are born to one heavy star. This calculation is based on the assumption that in disc-shaped galaxies, like our own Milky Way, the big star-making zone is in the denser core of the galaxy. On the galaxy edges, H-alpha signals are far rarer. Until now, this has been taken as confirmation that few stars are made there because there is so little gas. But a study released on Wednesday by the British-based journal Nature says that the 230-to-1 ratio could be just a quarter of the real tally in the outer regions. A satellite mission has shown that large numbers of stars are being created in these overlooked areas. In galactic centres, where there are large clusters of high-mass stars, the 230-to-1 benchmark is probably still right, say the authors, of Germany's Bonn University. But on the galactic edges, where the star clusters are smaller, a rough benchmark is that around 1,000 light stars are born to every heavy star. Source: AFP http://news.sbs.com.au/worldnewsaustralia/a_star_is_born_and_there_are_more_of_them_than_thought_558967 Quote Share this post Link to post Share on other sites
