87 runaway stars mapped to trace Milky Way's dark matterAstronomers from China identified 87 hypervelocity stars traveling fast enough to escape the Milky Way's gravitational pull, with seven exceeding 800 km/s, using data from the Sloan Digital Sky Survey, LAMOST telescope, and Gaia satellite.The stars' spatial distribution points to origins linked to the Hills mechanism, where Sagittarius A*, the supermassive black hole at the galaxy's center, and the Magellanic Clouds fling stars away at extreme velocities after gravitational encounters.By tracing these runaway stars' trajectories backward, scientists can map the Milky Way's gravitational potential and dark matter distribution in the halo, which holds roughly five times more mass than ordinary matter.Source

87 runaway stars mapped to trace Milky Way's dark matter

Astronomers from China identified 87 hypervelocity stars traveling fast enough to escape the Milky Way's gravitational pull, with seven exceeding 800 km/s, using data from the Sloan Digital Sky Survey, LAMOST telescope, and Gaia satellite.

The stars' spatial distribution points to origins linked to the Hills mechanism, where Sagittarius A*, the supermassive black hole at the galaxy's center, and the Magellanic Clouds fling stars away at extreme velocities after gravitational encounters.

By tracing these runaway stars' trajectories backward, scientists can map the Milky Way's gravitational potential and dark matter distribution in the halo, which holds roughly five times more mass than ordinary matter.

Source