Discovering a New Exoplanet (IMAGE) Dartmouth College Caption Data on the brightness of a young star led to the discovery of exoplanet DS Tuc Ab. Red arrows mark 'transits' where the planet crossed between Earth and the planet's host star. The large, smooth variations are caused by the star, a result of its youth. Credit Elisabeth Newton Usage Restrictions Must credit: Elisabeth Newton License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.