PARIS: Using archival data from the Japan-led Suzaku X-ray satellite, astronomers have determined the pre-explosion mass of a white dwarf star that blew up thousands of years ago. 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.
“Mounting evidence indicates both of these mechanisms produce what we call type Ia supernovae,” said Hiroya Yamaguchi from NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “To understand how these stars explode, we need to study the debris in detail with sensitive instruments like those on Suzaku.”
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. The observation, made in October 2010 at energies between 5,000 and 9,000 electron volts, provided a total effective exposure of 19 hours.
