Scientists may now figure out the surface gravity of distant stars by analysing variations in their brightness, which could provide clues to whether the planets that orbit the stars are hospitable to life.
A team of astrophysicists developed a method to measure the surface gravity of distant stars. That will also help them determine the life-hosting properties of the planets in their orbit.
The team, led by a researcher at the University of Vienna, looked at the slight variations in the stars’ brightness to calculate their surface gravity. These stars are too far away from Earth to analyse using conventional techniques.
Variations in brightness occur due to the surface and convection turbulence – forces which are similar to the ones behind a pot of boiling water, scientists explain.
In a paper – published January 1 in the journal Science Advances – scientists noted that in astrophysics gravity is very important as it can tell a lot about the properties of stars, like their radius and mass. Apart from that it can also provide clues to the properties of planets orbiting said stars, and whether they are habitable.
Jaymie Matthews, co-author of the study and a professor of astrophysics at the University of British Columbia, said that if a planet orbiting a star is the right size and temperature to have water (like our planet), then it may also host life. All of this can be figured out by looking at the star’s properties first, he added.
According to Prof. Matthews, you cannot know the planet without knowing the star. Based on the size of the parent star, the size of an exoplanet or extrasolar planet can also be measures (since it is relative to the star size).
Kepler, a space observatory launched by the National Aeronautics and Space Administration (NASA), and the Canadian Microvariability and Oscillations of STars telescope (MOST) collected the data on the stars. Researchers then used the data to figure out the gravitational pull of distant stars.
More than 1,000 planets have been discovered by Kepler since its launch in 2009. About twelve of them are less than twice the size of our planet. They are also located in the habitable zones of their parent stars – that means that they have the right temperature to maintain liquid water.
Prof. Matthews expects that within the next twenty years, someone will announce the discovery of life on an exoplanet (a planet that orbits a star other than the Sun).
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