Galaxy's 'Heartbeat' For First Time Heard By Hubble Space Telescope
There is one galaxy that has a "heartbeat," say scientists. They are able to measure the effect of the light of pulsating older red stars on its nearby galaxies, according to HNGN.
Stars that age get brighter and begin to get swollen. They engulf planets that are close by, Yale University reported. And when they inch towards their death, the light from the stars actually begin to look as if they are pulsating.
"We tend to think of galaxies as steady beacons in the sky, but they are actually 'shimmering' due to all the giant, pulsating stars in them," said Pieter van Dokkum, the Sol Goldman Professor and chair of astronomy at Yale, and co-author of the study.
Till now, scientists had not measured the influence of these older stars on the light from distant galaxies that were visible through the earth's telescopes. Pulsating stars' light blending with other stars have a brightness that do not fluctuate.
"We realized that these stars are so bright and their pulsations so strong that they are difficult to hide," said Charlie Conroy, an assistant professor at Harvard, who led the research. "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 neighbors."
Researchers examined a series of images from the galaxy M87, situated in the constellation Virgo. The image was taken by the Hubble Space Telescope in a quarter of a year.
Scientists saw that 25 percent of the pixels from the images had brightness that was pulsating, giving the impression that the galaxy had a heartbeat. The team is planning to search for and measure the pulsations in alternate galaxies.
"Our models suggest that the pulsations will be stronger in younger galaxies, and that's something we'd love to test," said co-author Jieun Choi, a Harvard graduate student.
With age, the brightness is expected to dim. Still, the pulsations will continue for a long while more, scientists are convinced.
"Cardiac arrest is not expected until a trillion years from now," van Dokkum said. "That's a hundred times longer than the age of the universe."
The study was published recently in the journal Nature.