A new study details a fascinating way to determine the pull of gravity at a distant star’s surface. In fact, it might even prove to be a way for scientists to determine whether those stars can host life in one way or another.“If you don’t know the star, you don’t know the planet,” explained UBC Professor Jaymie Matthews, study co-author. “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.”Matthews and her co-study lead Thomas Kallinger of the University of Vienna came up with a technique known as autocorrelation function timescale, or timescale technique, which utilizes slight variations in distant stars’ brightness, as documented by NASA’s Kepler mission and others.
Future satellites sent to outer space, the authors add, would search for so-called “Goldilocks Zones” of planets, which are not too hot, not too cold, but ideal for liquid oceans of water, and maybe even alien life forms.The timescale technique is capable of measuring surface gravity with a 4 percent accuracy rate for stars that are too far away and faint for conventional methodologies. Surface gravity depends on the mass of a star and its radius, and with that in mind, astronomers would be able to better determine the mass and size of these far-away beings.
The researchers believe that their technique would add a lot to the study of stars and planets beyond our solar system, including many that are way too far away for standard methods to determine their basic properties.As Kallinger concluded, the timescale technique is a “simple but powerful” method that could take information from the above searches to “help understand the nature of stars like our Sun and to help us find planets like our Earth.”