NASA's twin Voyager spacecraft have given astronomers their first direct look at emissions important for estimating the rate at which the Milky Way is making stars, opening a new avenue for studying star-forming regions in the galaxy.
NASA's twin Voyager spacecraft have given astronomers their first direct look at emissions important for estimating the rate at which the Milky Way is making stars.
The emissions are known as Lyman-alpha emissions. Their direct detection opens a new avenue for studying star-forming regions in the galaxy, according to a study published in the Dec. 2 issue of the journal Science.
Until now, astronomers have had to rely on another type of emission as a stand-in for gauging star-forming rates in the Milky Way and in other galaxies.
But the theoretical underpinnings that gave researchers the OK to use this surrogate haven't been tested against the real cosmos.
With future measurements from new spacecraft, researchers finally will be able to subject the surrogate to reality check.
"This is a pioneering observation," says Jeffrey Linsky, a researcher at the University of Colorado's Joint Institute for Laboratory Astrophysics in Boulder, Colo., who was not part of the research project.
Star-formation rates represent a critical element in the story of how galaxies form and evolve. Of particular interest, Dr. Linsky says, is the formation of so-called first-generation stars and how that leads to the birth of second-generation stars like the sun.
As the name implies, first-generation stars are the first to form as regions within vast, cold clouds of dust and hydrogen collapse under their own gravity and heat up. At a critical point, pressures and temperatures at the center of each ball of gas become so great that the hydrogen atoms fuse together to form heavier elements. This process releases enormous amounts of energy, igniting the stars.