Spooky ‘Graveyard’ Of Dead Stars Discovered As ‘Galactic Underworld’ Revealed For First Time
Astronomers have found a graveyard that stretches three times the height of the Milky Way.
The Milky Way kicks-out dead stars and one could be floating close to the solar system according to scientists working on a new map of “ghost” stars.
A new chart of the corpses of once massive stars—that have since collapsed into black holes and dense, small neutron stars—reveals a graveyard three times the height of the Milky Way.
About a third of the dead stars have been jettisoned from the galaxy.
When stars about eight times the mass of our Sun exhaust their fuel they collapse and blow apart in supernova explosions, eventually becoming either a neutron star or a black hole.
It’s the force of the supernova that creates them that’s responsible for them being ejected from the galaxy, suggests the authors of a newspaper published in Monthly Notices of the Royal Astronomical Society. Since they’re dark they’ve escaped detection until now when a model of their lifecycles was created to pinpoint where the stars were born, where they went supernova and where they ended up.
Point cloud top-down and side-view of the galactic underworld of the Milky Way
“One of the problems for finding these ancient objects is that, until now, we had no idea where to look,” said Professor Peter Tuthill, co-author on the paper, at the Sydney Institute for Astronomy in Australia. “The oldest neutron stars and black holes were created when the galaxy was younger and shaped differently, and then subjected to complex changes spanning billions of years. It has been a major task to model all of this to find them.”
In the maps they produced the spiral arms of the Milky Way vanish, with a side-on view showing a “galactic underworld” as a halo around our galaxy thanks to the kinetic kick given to the dead stars by their supernova explosions.
“Perhaps the most surprising finding from our study is that the kicks are so strong that the Milky Way will lose some of these remnants entirely,” said Dr Ryosuke Hirai, a co-author on the paper, from Monash University. “They are kicked so hard that about 30 percent of the neutron stars are flung out into intergalactic space, never to return.”
Even the local stellar neighbourhood around our Sun is likely to have these ghostly visitors passing through. “Statistically our nearest remnant should be only 65 light years away—more or less in our backyard, in galactic terms,” said Tuthill.
Wishing you clear skies and wide eyes.
