Thousands of newborn stars orbit the solar system, all enclosed in a strange formation known as the Local Bubble. Astronomers have now figured out how they linked. The birth of these newborn stars in the last 14 million years is due to the emergence of this huge bubble, a 1,000-light-year-wide emptiness. Researchers discovered that all the newborn stars – and seven locations that are still actively star-forming – within 500 light-years of us sit on the surface of this bubble, according to a study published in the journal Nature.
Researchers were able to travel 14 million years back in time, to a time when over a dozen supernovae exploded. The material driven by these cosmic explosions created winds that swept up the interstellar medium, forming an expanded shell. The shell’s fragments shattered into molecular clouds, some of which generated new stars in the previous few million years and others that are still forming new stars now. In a statement, astronomer, and data visualization expert Catherine Zucker of the Space Telescope Science Institute said, “This is actually an origin narrative; for the first time we can explain how all nearby star creation began.”
“Over millions of years, around 15 supernovae have gone off to generate the Local Bubble that we see today,” says the researcher. The speed of the bubble’s expansion has reached a halt, although it continues to grow at a rate of 6.5 kilometers (4 miles) per second. Data from the European Space Agency’s Gaia observatory, as well as theoretical models, enabled this investigation.
“This is a wonderful detective narrative, driven by both data and theory,” said Alyssa Goodman, study co-author and founder of glue, the data visualization program that enabled the finding, a Harvard professor and astronomer at the Center for Astrophysics. “Using a number of independent clues, such as supernova models, stellar movements, and beautiful new 3D maps of the material surrounding the Local Bubble, we can piece together the history of star creation around us.”
Any of those chaotic explosions and interstellar winds had nothing to do with the Solar System. It was only afterwards that it entered the scene, and it happened to be right in the middle of everything. “Our Sun was far distant from the action when the first supernovae that generated the Local Bubble went off,” said co-author Joo Alves, a professor at the University of Vienna.
“However, the Sun’s course through the galaxy carried it directly into the bubble approximately five million years ago, and the Sun currently sits – almost by chance – virtually in the bubble’s center.” The team intends to map more of these bubbles and investigate how they interact with the rest of the galaxy’s population. Understanding their evolution will help us understand the links between the death of stars and the formation of new ones.
