Scientists find a ring of gas around a white dwarf in the constellation Virgo. Don’t go thinking it’s an opportunity for explorers to get high or anything; this ring contains iron and other metals in gaseous state. Pretty hot. And unusual.
The research team led by Dr Boris Gänsicke and Professor Tom Marsh from the University of Warwick‘s Department of Physics found this unusual gas disc around a relatively young white dwarf star called SDSS1228+1040. It is located in the constellation Virgo and it is around 463 light years distant from our solar system. The star became a white dwarf around 100 million years ago, and is still fairly hot with a surface temperature around 22000 degrees.
The team observed double-peaked emission lines superimposed on the white dwarf’s starlight caused by iron, magnesium and calcium from material in the vicinity of the star. This indicated that they were dealing with a disc of metal-gas orbiting close around the star (around 1.2 solar radii or roughly half a million miles). The observations also show that we are looking nearly edge-on to the ring around the white dwarf.
The likely origin of the disc is an asteroid, of at least 50 kilometres in size, which approached close enough to the star to be broken up by tides generated from the gravitational forces of the white dwarf. Those disrupted remains then entered a close orbit around the star and is evaporated by the radiation from the white dwarf.