science & techESO videos

A dead star is surrounded by two discs of gas, likely fed by leftover planetesimals

the gist

Astronomers using the Very Large Telescope have found a rare debris system around the white dwarf J1328-1450, the dead core of a star similar to our Sun. Instead of a single disc, the star is circled by two discs of gas. These are thought to be maintained by planetesimals, small rocky bodies left over from planet formation that survived the star's death. As the planetesimals orbit, they collide with dust grains and release gas, which feeds the discs. The find shows how material can persist around a white dwarf long after its star has burned out.

so what

It suggests that rocky remnants of planetary systems can survive stellar death and keep evolving. Studying them is one of the few ways to learn what happens to the building blocks of planets around stars like our Sun.

ESO · CC BY 4.0

Image: ESO videos