White dwarf with gas ring. Computer artwork of the white dwarf star SDSS1228+1040, orbited by a glowing metal-rich ring of gas. The star is believed to have turned into a white dwarf star 100 million years ago. The gaseous disc orbiting the white dwarf is a relatively rare phenomenon. It is likely to have originated from a large asteroid being broken up by the star's powerful gravitational field and then being vaporised by its radiation. SDSS1228+1040 could be an example of what may happen to the solar system in 5-8 billion years' time, when the Sun becomes a white dwarf. SDSS1228+1040 is located in the constellation Virgo, some 463 light years away from Earth.