Scientists find that some stars are ‘breaking up’ with our Milky Way galaxy

Scientists have recently made a fascinating discovery: certain stars within our Milky Way galaxy are leaving and being ejected into intergalactic space, embarking on an uncertain journey for the rest of their lives.

In an effort to comprehend this peculiar phenomenon, a team of astronomers investigated the most massive among these runaway stars, aiming to understand how and why they departed from their galactic home.

The astronomers reached their conclusions while analyzing the velocity distribution, a metric used when studying a field of stars in the Milky Way. The general velocity dispersion of the star population reflects the galaxy’s rotation. Any star deviating from the galaxy’s rotation becomes apparent to astronomers.

This unusual occurrence caught the attention of scientists working with two extensive star catalogues, the Galactic O-Star Catalog (GOSC) and the Be Star Spectra (BeSS). These catalogues encompass various types of massive stars, such as O-type stars and Be-type stars, and their subtypes.

Lead author Mar Carretero Castrillo, a post-graduate researcher at the Institute of Cosmos Sciences, University of Barcelona, shared their findings in a study titled “Galactic runaway O and Be stars found using Gaia DR3,” which is set to be published in the journal Astronomy and Astrophysics.

Despite these intriguing findings, the exact number of runaway stars departing from our galaxy remains unknown. While an estimate suggests around 10 million runaway stars in the Milky Way, this figure is yet to be confirmed. Researchers are actively pursuing further investigations to uncover the secrets of these stars’ mysterious journeys into intergalactic space.