A Study of 3C 397, a Supernova Remnant (IMAGE) NASA/Goddard Space Flight Center Caption This is a study of 3C 397, a supernova remnant shown here in X-rays from NASA's Chandra X-ray Observatory (purple) and Suzaku (blue), indicates the blast arose from a single white dwarf that accumulated matter from a normal companion star. The white dwarf exploded as its mass neared 1.4 solar masses. Credit NASA/Suzaku and NASA/CXC, DSS, and NASA/JPL-Caltech Usage Restrictions None 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.