[News] A new accurate map reveals a hidden structure in the Milky Way

[SougarLord]

 

A scientific team led by researchers from the Center for Astrobiology (CAB, CSIC-INTA), has drawn the most detailed map to date of massive blue stars in the solar neighborhood, discovering in it a hidden structure, baptized as the Cepheus spur. This structure extends over the galactic plane connecting the spiral arm of Orion with that of Perseus.

 

Massive blue stars (also known as OB stars) have a peculiarity that makes them especially interesting to astrophysicists: they have a short-lived life of a few million years. Thus, just as the dating of rocks reveals the level of geological activity of a planet, the presence of OB stars in the Milky Way is an indicator of activity in our galaxy, since they reveal regions of star formation. Where we find them we can say that the galaxy is "alive", as new stars are forming. It also happens that these short-lived stars do not have time to move away from the areas where they are born, the spiral arms, so they are excellent references for mapping these galactic structures.

 

To this end, a team of researchers led by the Center for Astrobiology (CAB, CSIC-INTA) has carried out an exhaustive update of the ALS (Alma Luminous Stars) catalog, the largest existing catalog of massive OB stars in our galaxy, which has with almost 20,000 objects. For months, researchers have crossed the old data from each star with the data recently obtained from ESA's Gaia mission, obtaining a completely up-to-date catalog. The new data, recently published in the Monthly Notices of the Royal Astronomical Society (MNRAS), has allowed the team to draw the most detailed map of the spiral arms of the Milky Way for the first time.

Above the galactic plane

The map is so precise that it has allowed the scientific team to discover something that no one has seen before: a branch of our spiral arm (that of Orion) about 10,000 light-years long that extends outward in the direction of the next arm ( that of Perseus), also rising above the plane of the Galaxy. Researchers have named this newly discovered structure "the Cepheus spur": spur because it is how they are called this type of structure between arms and Cepheus because it is the constellation where it is most prominent.

 

“It is interesting to note that the huge amount of data obtained with the Gaia mission and the use of statistical tools has allowed us to draw interesting general conclusions about our environment, such as indications of the warping of our galaxy (like a plank that has been warped by humidity) and the corrugations (contractions) of the disk, which are probably relics of the convulsive evolution of the Milky Way, ”says Michelangelo Pantaleoni, CAB researcher and lead author of the study.