Hubble Space Telescope Measures The Motion Of Stars In Nearby Galaxy
Scientists have been able to measure the average rotation rate of many individual stars situated in the central part of the neighboring galaxy - the Large Megallanic Cloud.
With the help of NASA's Hubble Space Telescope, astronomers for the very first time were able to precisely measure the average motion of the galaxy. The movement of galaxy was based on the movement of its stars. The calculation was possible because of the telescope's high resolution.
"If we imagine a human on the moon, Hubble's precision would allow us to determine the speed at which the person's hair grows," Roeland van der Marel of the Space Telescope Science Institute in Baltimore said in a press release.
"This precision is crucial, because the apparent stellar motions are so small because of the galaxy's distance. You can think of the LMC as a clock in the sky, on which the hands take 250 million years to make one revolution. We know the clock's hands move, but even with Hubble we need to stare at them for several years to see any movement."
According to the results published, the neighboring galaxy completed a rotation every 250 million years. The time approximately equals the sun to complete a rotation around the center of the Milky Way Galaxy.
"Studying this nearby galaxy by tracking the stars' movements gives us a better understanding of the internal structure of disk galaxies," said Nitya Kallivayalil of the University of Virginia in Charlottesville, Va in the press release, "Knowing a galaxy's rotation rate offers insight into how a galaxy formed, and it can be used to calculate its mass."
"The LMC is a very important galaxy because it is very near to our Milky Way," added van der Marel in the press release. "Studying the Milky Way is difficult because you're studying from the inside, so everything you see is spread all over the sky. It's all at different distances, and you're sitting in the middle of it. Studying structure and rotation is much easier if you view a nearby galaxy from the outside."
The results are published in the journal Astrophysical Journal.