Look up in the sky at night. That flickering you see from the stars can be used to determine the star’s age. The technique was recently used in a study to determine the age of Galaxy Messier 87, where astronomers measured the pulses from a star within the galaxy.
Even though it can be tough to tell just by looking at stars in the sky at night, they are constantly changing, going through their own life cycles. As they near the end of their lives, they grow to a large size, sometimes swallowing nearby planets. Afterwards their light begins to pulsate over the course of a few hundred days reports the Harvard-Smithsonian Center for Astrophysics (CfA). There are a number of stars going through this phase in the Milky Way galaxy right now.
The study, recently published in the journal Nature, describes how three months’ worth of Hubble Space Telescope photos of Galaxy M87 in 2006 has provided proof to the theory that a galaxy’s age can be determined by its pulsating “heartbeat”.
Harvard assistant professor and lead researcher Charlie Conroy explains that the change in light from the stars was obvious and they were curious if it was possible to separate the changing light from the static light from nearby stars.
We realized that these stars are so bright and their pulsations so strong that they are difficult to hide. 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.
By using the data collected, they were able to determine the estimated age of M87 to be around 10 billion years which coincides with the previously calculated age.
Theoretically these heartbeat patterns should not be specific to M87 and the researchers are planning to look at pulses from other galaxies next reports Tech Times. Graduate student and co-author of the study, Jieun Choi, expects to find that the pulses will be stronger in younger galaxies. “Our models suggest that the pulsations will be stronger in younger galaxies, and that’s something we’d love to test”, he said.
