NASA | MSFC | SAO | Chandra X-ray Observatory | 2018 Dec 03
Astronomers have detected a bright X-ray outburst from a star in the Small Magellanic Cloud, a nearby galaxy almost 200,000 light years from Earth. A combination of X-ray and optical data indicate that the source of this radiation is a white dwarf star that may be the fastest-growing white dwarf ever observed. ...
A new study based on observations with NASA's Chandra X-ray Observatory and Neil Gehrels Swift Observatory has reported the discovery of distinctive X-ray emission from a binary system containing a white dwarf called ASASSN-16oh. The discovery involves the detection of low-energy — what astronomers refer to as "soft" — X-rays, produced by gas at temperatures of several hundred thousand degrees. In contrast, higher-energy X-rays reveal phenomena at temperatures of tens of millions of degrees. The X-ray emission from ASASSN-16oh is much brighter than the soft X-rays produced by the atmospheres of normal stars, placing it in the special category of a supersoft X-ray source. ...
Unconventional Origin of Supersoft X-ray Emission from a White Dwarf Binary ~ Thomas J. Maccarone et al
- Nature Astronomy (online 03 Dec 2018) DOI: 10.1038/s41550-018-0639-1