The sequence of supernovae may have caused the formation of a huge “bubble” of stars

Thousands of stars that form Milky Way neighborhood It is the result of a series of more than a dozen supernova explosions that occurred 14 million years ago, which led to the emergence of a large bubble, responsible for the formation of all the young stars close to us. The discovery was made by astronomers at the Astrophysical Center | Harvard and Smithsonian (CfA) and Space Telescope Science Institute (STScI).

The authors investigated a large bubble with a dense surface, resulting in the emergence of thousands of “baby stars– and the Earth is right in the middle of this structure. “That’s really an origin story; For the first time, we can explain how all nearby stars begin to form, said Catherine Zucker, a co-author on the study.

The so-called “local bubble” was discovered by astronomers in the 1970s, who observed that no stars had formed in it for about 14 million years. The only stars that were in the bubble were already there, even before the structure appeared, or formed outside of it, and crossed it. This would suggest, then, that Supernova explosions It would release the materials needed to form new stars.

In the new study, the authors mapped regions of star formation near the bubble. Although its existence has been known for decades, only now have they been able to see and understand how it was formed, as well as the effect of the gas surrounding it. They also created an interactive 3D model, which reveals all young stars and star-forming regions 500 light-years from Earth in the Local Bubble.

The model was produced based on new data science and data science techniques and shows how a series of supernovae, which first exploded 14 million years ago, pushed the interstellar gas forward. This is how the bubble-shaped structure was born, with a perfect surface for its formation new stars. Today, it is already known that the bubble contains seven molecular clouds, which are considered star-forming regions.

What is known about the Milky Way bubble

The study authors note that the bubble is not dormant and continues to grow slowly. “It is traveling at more than 20 km/h” and “has lost most of its force, and has practically stabilized in terms of speed,” he said. The velocity of the bubble’s expansion, along with the past and current trajectories of young stars on its surface, were derived from data obtained by The European Space Agency’s Gaia mission.

João Alves, co-author of the study, explains that when the first supernova that created the Local Bubble exploded, the sun was still far from all action. “But about five million years ago, it was sun way Through the galaxy he brought him straight into the bubble, and today he is, fortunately, roughly in the center of it,” he said. Practically speaking, this means we have an “important place” to observe the star-forming processes that occur on the bubble’s surface.

The team now plans to map the new star bubbles to get a full 3D view of their locations, shapes and sizes. By analyzing the bubbles and their relationship to one another, they hope to understand the role stars play in forming others at the end of their lives, along with influences on star structure and evolution. Milky Way galaxies.

The article containing the study results was published in the journal Nature.

source: temper nature; via: Harvard Center for Astrophysics