Astronomers develop new technique for gravity calculation for distant stars

Astronomers develop new technique for gravity calculation for distant stars

Calculation of gravitational pull at surface of distant stars isn’t an easy task and there is a chance for high degree of error. Astronomers from Universities in Canada, Austria, France and Germany have worked on a collaborative project to develop a new technique for estimating gravity at distant stars. The gravitational pull is an important factor in ascertaining the possibility of life on planets orbiting a specific star. The new technique for calculating gravity has been termed as autocorrelation function timescale technique.

The research was led by University of Vienna's Thomas Kallinger and the paper was co-authored by University of British Columbia professor Jaymie Matthews. The research paper has been published in the journal Science Advances. Astronomers from Germany, France and Australia also worked on the current project.

Professor Kallinger informed that the timescale technique is simply but can act as a powerful tool for understanding distant stars. It can also help in finding exoplanets that can support life.

The research team used data from Kepler Space Telescope to check the variations in the brightness of distant stars. The research team evaluates the timescale of turbulence and vibration at a star's surface, based on its brightness variations, to calculate its surface gravity. The research team claimed that gravity for a distant star could be calculated with accuracy up to 4 percent.

For distant stars and those which are too faint, current methods to measure gravity are ineffective. The size of distant stars can be calculated using the current technique. The research team informed that gravity is dependent on mass and radius of stars.

Gravity of surface of Sun could be nearly 20 times that on our planet Earth. Gravitational pull on a red giant star can be 50 times weaker than the pull on Earth.

Professor Jaymie Matthews said, “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 research paper said, “Future space satellites will hunt for planets in the 'Goldilocks Zones' of their stars. Not too hot, not too cold, but just right for liquid water oceans and maybe life. Future exoplanet surveys will need the best possible information about the stars they search, if they're to correctly characterize any planets they find.”

The method can be applied to data from these searches to help understand the nature of stars like our Sun and to help find other planets like our Earth, says Dr Kallinger.

Dr Kallinger said, "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."

Research team contacts

Thomas Kallinger, University of Vienna, Austria thomas.kallinger@univie.ac.at
Jaymie Matthews, UBC Physics & Astronomy, Vancouver, Canada matthews@astro.ubc.ca

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