Towards the end of their lifetime, they start to throb which makes their light increase and decrease in brightness every several hundred days.
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The Astronomers have spotted quite a few stars, but no research looked into the effects of stars on the light coming from more distant galaxies.
Hubble Space Telescope photograph of the galaxy M87, which is 50 million light years from Earth.
Conroy says that the team used M87 because it was the only galaxy for which they had all the data they needed.
Researchers examined a series of images from the galaxy M87, situated in the constellation Virgo. Subjected to rigorous analysis, the images of the red stars in the elliptical galaxy Messier 87 showed something spectacular.
And speaking of pulsating variable stars, according to astronomers at Harvard and Yale, they’ve measured the stellar pulses in this galaxy. Looking at a galaxy is like looking down on a terrestrial city from space: we can see the stellar downtowns and suburbs, and even the layout of a few neighborhoods, but we generally don’t notice the effect of individual families turning their lights on and off. Since our sun will go through this same phase when it nears the of its life cycle, the study offers a sneak-peak to the future that awaits our own solar system, he added.
Till now, no one was able to ponder upon the effects of these stars on the light arriving from aloof distant galaxies. “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”.
Pieter van Dokkum from Yale University revealed that one in four pixels in the Hubble image changes with time, meaning, they’ve detected the pulses.
The discovery offers a new way of measuring the age of a galaxy, because the strength and speed of a galaxy’s heartbeat varies depending on its age.
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.
“It’s as if we’re taking the pulse of the galaxy”, Dr Conroy said. The regular up and down changes in brightness are reminiscent of a heartbeat.
The stars in this galaxy probably formed a very long time ago – maybe 10 billion years ago – and if that’s true then this galaxy is a fossil relic from a much earlier time in the universe.
The team found that M87 is about 10 billion years old, a number that agrees with previous estimates using different techniques.
What’s next? Every galaxy should show similar pulsing patterns.
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‘Cardiac arrest is not expected until a trillion years from now, ‘ von Dokkum said. This new finding is paving the way for the researchers to take the pulse of other galaxies.
