Planets Born to a Dying Star

Young stars and new planets go hand-in-hand. But that might not always be the case. An international team of astronomers have discovered a situation where material shed from a dying star is being captured into a planetary disk around a binary companion.

The dying star is Mira A, located about 350 light years from Earth in the constellation of Cetus. It’s a variable star, changing brightness by a factor of 1,000. Over the course of 11 months, it varies from nearly invisible to bright enough to be seen with the unaided eye. Mira A used to be a star very similar to the Sun, but now it’s dying, shedding dusty outer layers into space.

Fortunately, there’s another star there to capture some of this material. Its binary partner Mira B is an ordinary star, with about half the mass of the Sun. It’s capturing about 1% of the material flying off into space from Mira A.

In another million years or so, Mira A will finally stop kicking, and become a white dwarf star. The disk around Mira B will stop gathering material, and begin forming everything it collected into a system of planets.

This discovery will give astronomers a new way to go looking for planets; around the binary partners of dying stars.

Original Source: Keck News Release