Scientists probe innards of distant star

An international team of scientists says a new way to measure the internal properties of stars can offer a more accurate assessment of their orbiting planets. Previously, scientists inferred stars' properties such as radius, mass and age through observations of their brightness and color, but the results were often not accurate enough to make assumptions about their orbiting planets, they said. Now, a U.S.-German team of scientists, reporting in the Proceedings of the National Academy of Sciences, has described a new approach to characterize star-planet systems: asteroseismology. The technique identifies the internal properties of stars by measuring their surface oscillations, comparable to the way seismologists use earthquake oscillations to examine the Earth's interior. The researchers, from New York University, Princeton University and the Max Planck Institute for Solar System Research, used asteroseismology to examine HD 52265, a star approximately 92 light years away and nearly 20 percent more massive than our Sun known to have an exoplanet in orbit around it. They were able to make several assessments of the star's traits, including its mass, radius, age and -- for the first time -- its internal rotation. They were able then to use these findings to make a more definitive assessment of its orbiting exoplanet, including its true mass of roughly twice that of our solar system's planet Jupiter.