A star-producing cosmic bubble envelops our solar system | Smart News
For the first time, researchers have studied a series of events beginning 14 million years ago that caused Earth’s galactic neighborhood to be enveloped by an ever-expanding cosmic bubble, forming all nearby stars, explains a press release. Called the local bubble, the expanse is 1,000 light-years wide. Within 500 light-years from Earth, all of the stars and star-forming regions are on the surface of the local bubble, but not inside it, giving clues as to why the Earth sits in a part of the Milky Way that is largely empty, reports Denise Chow for NBC News.
Scientists have suspected the existence of the giant bubble for decades. However, it was only recently that astronomers observed the net, its shape and its range. Astronomers from the Harvard-Smithsonian Center for Astrophysics (CfA) and the Space Telescope Science Institute (STScI) published the study this week in Nature.
The local bubble formed from a series of supernovae, or powerful explosions that occur when stars collapse at the end of their lifespans, NBC News reports. These explosions have occurred near the center of the vacuum and have propelled gas through space for the past 14 million years. The shock wave gathered clouds of gas and dust into a thick, hollow, icy shell that formed the surface of the local bubble, says Catherine Zucker, lead study author and astronomer at the Center for Astrophysics. , to Isaac Shultz for Gizmodo. The gas and dust clouds provided enough fuel for the star forming regions on the surface of the bubble.
Using data visualization software, the team mapped the asymmetric bubble. Over millions of years, at least 15 supernovae have erupted and pushed gas outward, creating a bubble where seven star-forming regions sit on the surface. Astronomers have also created beautiful 3D maps of celestial matter in the local bubble.
When the bubble first formed, it was moving at around 60 miles per second, according to data collected by Gaia, a space observatory owned by the European Space Agency. Currently, the bubble continues to expand at four miles per second, Gizmodo reports.
Astronomers suspect that the solar system is located in the middle of the bubble because it is much older than 14 million years, for Gizmodo. When the first supernova created the local bubble, the sun was far from it, explains João Alves, an astrophysicist from the University of Vienna, in a press release. About five million years ago, the sun entered the local bubble, where it currently sits near the middle.
“When the local bubble started to form, Earth was over 1,000 light-years away,” Zucker said. Gizmodo. “We believe Earth entered the bubble about 5 million years ago, which is consistent with estimates of radioactive deposition of iron isotopes from supernovae in Earth’s crust from other studies.”
The researchers suggest that more star-forming bubbles are likely common throughout the Milky Way. Study author and CfA astronomer Alyssa Goodman – who founded Glue, the data visualization software that helped piece together the study’s maps – explains in a statement that statistically the sun would not be near the middle of a vast bubble if they weren’t common throughout the galaxy.
“The local bubble is where we find ourselves right now,” Zucker told NBC News. “We think the sun in its history has probably passed through many, many super bubbles.”
The team plans to map more cosmic bubbles to get a full 3D view of their shape, location and size. By mapping where the bubbles were in the vast expanse of space, astronomers can understand how these bubbles act as nurseries for stars, how the bubbles interact with each other, and how galaxies like the Milky Way evolved. over time, according to a statement.