Astronomers have known for decades that our solar system lies in the middle of a bubble in space about 1,000 light-years wide with incredibly young stars on its “surface,” but now researchers think they’ve found it. How did you get there?
In a new study published in Nature, astronomers from the Center for Astrophysics, Harvard and Smithsonian (CfA) and the Space Telescope Science Institute (STScI) used computer modeling to travel back in time to reproduce the evolution of the local bubble. Used because it is called.
Obviously, it took a lot of supernovae. About 14 million years ago, a relatively rapid sequence of stellar explosions — about 15 in total — pushed the interstellar gas and dust outward, carving a low-density cavity with a “edge” rich in dense gas and dust. It provides ideal conditions for this. Formation of new stars.
“We calculated that it took about 15 supernovae millions of years to form the local bubble,” said Katherine Zucker, an astronomer and data visualization specialist who worked on the project for the CFA and is now a NASA Hubble Fellow at STScI. “It’s really an origin story; For the first time, we can tell how all nearby stars began to form.”
Stars usually don’t just form on their own. They usually require some kind of push to force clouds of gas and dust to collide so that the hydrogen can begin to fuse and completely ignite in stellar furnaces.
The expansion of the local bubble is providing exactly the same perturbation to kickstart the star-formation process in the molecular cloud, and it’s still expanding when you read this.
“It’s coasting with about 4 mph,” Zucker said. “Although it has lost most of its oomph and plateaued a lot in terms of speed.”
Analysis: Wait, why didn’t we blow away all those supernovas?
If you’re wondering how our solar system survived 14 million years ago with 15 or so supernovae flying around, you’re right to ask this question.
Luckily for us, we weren’t really in the local bubble when it all started to take off. We are only passing through it at the moment, entering a bubble about five million years ago.
In about 5 million years, we’ll grow out of it as well, but for now, we essentially enjoy the sight of being surrounded by a stellar nursery.
“When the first supernova to form a local bubble went off, our Sun was far from in action,” said Joo Alves, a professor at the University of Vienna and a co-author of the study. “But about five million years ago, the Sun’s path through the Milky Way took it straight into the bubble, and now the Sun sits – just by luck – almost right at the center of the bubble.”
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