A group of international researchers found a way to measure the pull of gravity at the surface of distant stars, paving the way for the possible discovery of other worlds.
The key to identifying habitable worlds is determining the gravitational pull of distant stars that orbit such planets. Through the new technique, experts may be one step closer to achieving the dream of discovering life outside Earth.
The New Technique
The new method developed by experts is called autocorrelation function timescale technique. Also known as timescale technique for short, this strategy utilizes ingenious variations in the brightness of distant stars documented via satellites such as NASA's Kepler telescope and Canada's Microvariability and Oscillations of STars telescope (MOST).
Through the timescale technique, experts are able to measure the surface gravity of distant stars commonly not measured through conventional techniques. The accuracy rate for the new method is about 4 percent.
The surface gravity of a star is based on its mass and radius. Such concept is similar to the dependability of a person's weight to the mass and radius of the Earth. With the new technique, astronomers will be able to better estimate the masses and sizes of distant stars.
The timescale technique now raises the bar of studies in astronomy, particularly in investigations involving planets outside of the solar system. Because these planets are so far away, even the most fundamental properties of the stars that orbit them cannot be accurately measured, so a new range of improved techniques are necessary.
"The technique we present here is the first of that new generation," the authors wrote.
New World Discoveries
The work of the scientists led by Thomas Kallinger from the University of Vienna was based on Kepler data. The space telescope was launched in 2009 to look for transiting Earth-sized planets found in and near the habitable regions of stars that resemble the sun.
"If you don't know the star, you don't know the planet," said study co-author Jaymie Matthews from the University of British Columbia. He added that the size of an exoplanet depends on the size of its parent star. With this, people who think that they found a planet around a "sun-like" star may have fooled themselves into thinking they have discovered an Earth-sized world.
Matthews further said that their new technique can ultimately determine a star's size and brightness and whether it is near a planet that possesses the right temperature and size to hold water oceans and perhaps, life.
In the future, satellites may soon target planets in the habitable zone, or the "Goldilocks Zone," of its stars, where the temperature is neither too high nor too cold but just right for conditions such as liquid water to exist.
Kallinger said that the timescale technique is a basic but very efficient tool that can be applied to satellite studies to help comprehend the nature of stars like the Earth's sun and discover other Earth-like planets.
The study was published in the journal Science Advances on Friday, Jan 1.
