NEW YORK: Astronomers have determined the pre-explosion mass of a white dwarf star that blew up thousands of years ago and the measurement strongly suggests the explosion involved only a single white dwarf, ruling out a well-established alternative scenario involving a pair of merging white dwarfs.
The researchers analyzed archival observations of a supernova remnant named 3C 397, which is located about 33,000 light-years away in the constellation Aquila. Astronomers estimate this cloud of stellar debris has been expanding for between 1,000 and 2,000 years, making 3C 397 a middle-aged remnant. The team made clear detections of elements crucial to weighing the white dwarf using data from Suzaku’s X-ray Imaging Spectrometer, which was launched in 2005. The observation, made in October 2010 at energies between 5,000 and 9,000 electron volts, provided a total effective exposure of 19 hours.
