Brightness measurements can help gauge size, stage of evolution
The key to learning about distant stars is as simple as watching them flicker.
Stellar brightness measurements from NASA’s planet-hunting Kepler space telescope can pin down the once-elusive physical properties of about 170,000 stars and the planets orbiting them, scientists report in the Aug. 22 Nature. The new technique can translate modest fluctuations in starlight over several hours into a star’s size, surface gravity and stage of life.
“All this information is encoded in a star’s brightness in such a wonderfully simple way,” says Vanderbilt astrophysicist and study coauthor Keivan Stassun.
For four years, the now-moribund Kepler (SN Online: 8/15/13) stared at the stars within a patch of sky, looking for eclipsing planets. Kepler homed in on several hundred for meticulous scrutiny. By studying subtle changes in the brightness of these select stars, astronomers have been able to