Africa-Press – South-Sudan. The Local Bubble cavity was discovered almost half a century ago, but it remained a mystery as to how the gap in the interstellar media came into being and how it evolved over the years, not to mention simpler questions about its size and shape.
An international team of astronomers led by the Harvard & Smithsonian Center for Astrophysics (CfA) claims to have found crucial information about the Local Bubble, an enigmatic void located in our galaxy.
According to the findings of their study, published on 12 January in the journal Nature, the researchers analysed data obtained by the Gaia space observatory, in particular shapes, positions and motions of young stars surrounding the bubble as well star-forming regions. The astronomers found that they all lie on the void’s surface, which they say allowed them to “turn the clock back” and see how the stars evolved.
The results showed that the Local Bubble was created around 14 million years ago when a series of stellar explosions – known as supernovae – occurred. These explosions pushed interstellar gas outwards, creating a bubble-like structure with a surface that’s ripe for star formation.
Astronomer Catherine Zucker of the Space Telescope Science Institute, said the findings provide strong support for the theory of a supernova-driven star formation, “where stellar death can trigger stellar birth”.
Scientists say the Local Bubble continues to grow at about 4 miles (6.4km) per second and is shaped as a peanut. Their next plan is to find other bubbles inside the Milky Way and examine their history, something researchers say will help them to understand better the formation of stars and evolutionary history of our galaxy.