Milky Way’s white dwarfs show the galaxy’s history

In a study published in the scientific journal Monthly Notices of the Royal Astronomical Society, a team of researchers made new discoveries about how white dwarfs move.

Thanks to observations from the Gaia Space Telescope, we were able for the first time to detect the 3D velocity distribution of the largest catalog of white dwarfs to date. This gives us a detailed picture of their velocity structure, absolutely unparalleled,” says Daniel Mikola, a doctoral student in astronomy at Lund University.

White dwarfs move in different ways

Thanks to Gaia, researchers have established positions and velocities for about 1.5 billion stars. But only now were they able to fully focus on the white dwarfs in the vicinity of the Sun.

We have been able to determine the speeds and patterns of white dwarfs’ movement. Gaia revealed two parallel sequences of white dwarfs when looking at their temperature and brightness. When we study them separately, we can see that they move in different ways, possibly as a result of their different masses and ages, says Daniel Mikkola.

The date of the Milky Way is set

The results can be used to develop new simulations and models to further map the history and evolution of the Milky Way. By increasing knowledge of white dwarfs, researchers hope to be able to straighten out a number of question marks surrounding the birth of the Milky Way.

This study is important because we have learned more about the closest regions of our galaxy. The results are also interesting because our star, the Sun, will one day turn into a white dwarf just like 97 percent of all stars in the Milky Way galaxy, says Daniel Mikkola.

Scientific study:

White dwarf speed distribution in Gaia EDR3Monthly Notices of the Royal Astronomical Society .

call:

Daniel Mikola, PhD student, Department of Astronomy and Theoretical Physics, Lund University, [email protected]