DISTANT GALAXIES HAVE A HEARTBEAT
PULSARS IN GALAXY M87 give the galaxy a ‘heartbeat’, potentially providing researchers a new way to measure the galaxy’s age.
Towards the end of their lives, certain stars begin to pulsate, growing and decreasing in size and brightness over the course of a few hundred days. We’ve seen these stars within our own Galaxy, but little thought has been given to the effects of these stars in other galaxies.
“We realised that these stars are so bright and their pulsations so strong that they are difficult to hide,” says Charlie Conroy from Harvard University. “We decided to see if the pulsations of these stars could be detected even if we could not separate their light from the sea of unchanging stars that are their neighbours.”
Now researchers will begin to take the pulse of other galaxies, hoping to find a new way to age galaxies, something that is currently difficult to do. “Our models suggest that the pulsations will be stronger in younger galaxies, and that’s something we’d love to test,” says Jieun Choi from Harvard University. http://hubblesite.org
M87, some 50 million lightyears from Earth in Virgo, is a supergiant elliptical galaxy