Dead star with a glowing shock wave defies expectations

Astronomers using the European Southern Observatory’s Very Large Telescope found a bright, multicolored bow shock around the white dwarf RXJ0528+2838 about 730 light-years away, despite no detected accretion disc. The structure appears to trace an outflow active for at least 1,000 years, and researchers report a strong magnetic field as a possible partial explanation.

Astronomers have reported an unexpected glowing bow shock around the white dwarf RXJ0528+2838, observed with the European Southern Observatory’s Very Large Telescope. The object is a dead star in a binary system with a Sun-like companion and lies about 730 light-years from Earth. The bow shock appears bright in red, green and blue emission and is originating from the binary system. Researchers say the white dwarf shows no sign of a surrounding accretion disc, making the persistent outflow surprising. Key details: - The central object is a white dwarf in a binary system with a Sun-like companion. - The bow shock was imaged and mapped in detail using the Very Large Telescope and is emitting in multiple colors. - No accretion disc, which commonly fuels outflows in similar systems, was detected around the white dwarf. - The shape and size of the bow shock indicate material has been expelled for at least about 1,000 years. - Researchers report a possible explanation involving a strong magnetic field channeling material without a disc, but that alone would explain only a shorter timescale. Summary: The finding challenges the standard view of how matter moves and interacts in some binary systems, because a discless white dwarf appears to be driving a long-lived outflow. Undetermined at this time.