New “timescale technique” to find more accurate gravity of distant stars

25 Feb 2019

In a recent advancement, astronomers from Germany, Australia and France along with other scientists have discovered a new method to measure the surface of a star’s gravitational pull, which is said to be very helpful in determining the gravitational pull of the planets which orbits any distant stars. Ultimately, to find out whether the gravitational pull supports life harbour over there.

The study of the new way to find the pull of gravity on distant stars has been published in the journal Science Advances. Thomas Kallinger from University of Vienna and Jaymie Matthews (involved UBC professor) led the research with the help of astronomers from Australia, Germany and France.

If scientists are able to measure the gravity on the surface of a star, they could find the weights (from the Earth) of any matter on that star. Your weight will not be same on every star, just imagine that those stars have a solid surface and you stand on it. Do you know that you weigh almost 20 times heavier on the surface of the Sun than the Earth? Higher the gravitational pull, higher the weight of any matter over there. A red giant star which has weak gravity can weigh you lighter than the Earth, almost 50 times lighter.

The new method to measure the gravity is called as the autocorrelation function timescale technique (timescale technique, in short), which calculates the gravitational pull of those stars by studying the precise variations in the star’s brightness. These brightness changes are being recorded by satellites, such as NASA’s Kepler missions and Canada’s MOST.

Co-author of this research, UBC Professor Jaymie Matthews, said in a statement:

“If you don’t know the star, you don’t know the planet. The size of an exoplanet is measured relative to the size of its parent star. If you find a planet around a star that you think is Sun-like, but is actually a giant, you may have fooled yourself into thinking you’ve found a habitable Earth-sized world. Our technique can tell you how big and bright is the star, and if a planet around it is the right size and temperature to have water oceans, and maybe life.”
“The timescale technique is a simple but powerful tool that can be applied to the data from these searches to help understand the nature of stars like our Sun and to help find other planets like our Earth,” said Kallinger, the study’s lead author.

According to the reports, the timescale technique can measure the gravity of distant and fainted stars with an accuracy of about 4 percent. Other factors can also be found through this technique such as those stars’ mass and radius, as the gravity of any planets depends on the mass and radius of those planets. Experts reviewed positively about the new technique and hoped to find out the most accurate information on any planets away from our Solar System.

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