Astronomers Intrigued By Impossible Structure Around Dead Star

"A dead star 730 light years away appears to be forming a powerful structure around itself - and despite their best efforts, astronomers aren't sure how. The cosmic corpse, designated RXJ0528+2838, is an incredibly dense stellar remnant known as a white dwarf, with a Sun-like star orbiting around it. This binary arrangement isn't uncommon throughout the universe, but what is strange is the structure surrounding the former body: a highly energetic and luminescent cloud known as a nebula,"

""Our observations reveal a powerful outflow that, according to our current understanding, shouldn't be there," said Krystian Iłkiewicz, a researcher at the Nicolaus Copernicus Astronomical Center in Warsaw, Poland, and co-lead author of a new study published in the journal Nature Astronomy, in a statement. White dwarfs are what's left over when stars of moderate mass like our Sun exhaust all their fuel, shed their outer layers, and expose a dense core."

"As it does so, the stolen matter forms a luminous ring around itself known as an accretion disc. Then, as the star slowly revolves around the galactic center and moves through space, it creates a shock wave in the nebula called a bow shock, which is a "curved arc of material, similar to the wave that builds up in front of a ship," explained coauthor Noel Castro Segura, a researcher at the University of Warwick in the UK, in the statement."

RXJ0528+2838 is a white dwarf in a close binary with a Sun-like companion, surrounded by a luminous, highly energetic nebula and a powerful outflow. No accretion disc is detected around the white dwarf, and high-resolution images from the Very Large Telescope rule out a recent nova as the nebula's origin. Typical formation mechanisms such as mass transfer forming an accretion disc or a bow shock from motion through the interstellar medium do not match the observations. The lack of detectable drivers leaves the outflow and nebula unexplained under current understanding of white dwarf binaries.

Read at Futurism