A team of astronomers has reconstructed the history of our local universe to understand the origin of the earliest stars. in a study published Today in nature, they describe an amorphous bubble 1,000 light-years wide that lies underground and is responsible for those stars.
Researchers believe, called the Local Bubble, it formed from a series of large eruptions that have blasted energy into space over the past 14 million years. These explosions were supernovae – spectacular collapses of stars that sometimes leave behind beautiful nebulae. In this case, supernovae also formed our neighborhood of the galaxy, 500 light-years away in any direction from Earth.
“We found that all nearby young stars that formed when powerful supernova explosions triggered an expanding shock wave, engulfing interstellar clouds of gas and dust in a cold dense crust that now forms the surface of the Local Bubble,” said study co-author Katherine Zucker. In an email to Gizmodo.
Zucker, an astronomer at the Center for Astrophysics, added | Harvard and Smithsonian.
The team modeled how the eruptions likely occurred over millions of years, pushing the gas out like a broom removing dust. When it arose, Zucker said, the bubble was likely moving outward at 60 miles per second. It’s still expanding today, but at a leisurely 4 miles per second. Interactive shapes of the bubble can be seen here.
Our solar system is at the center of the bubble, not at the edge. This is because, unlike the stars on the periphery of the local bubble, our solar system was born much longer than the last 14 million years.
“When the local bubble first started forming, Earth was more than 1,000 light-years away,” Zucker said. “We believe that the Earth entered the bubble about 5 million years ago, which is consistent with estimates of iron isotope deposits from the supernova in the Earth’s crust from Other studies. “
Local bubble-like file Shell Bear Taw, A cavity in the space between the constellations Perseus and Taurus. The Per-Tau shell has large clouds of gas, called molecular clouds, on its sides, and researchers believe the envelope is what remains of the supernovae that pushed the gas out. The latter team believes that the Local Bubble has a similar origin, but since it is 10 times larger, it likely requires slightly more firepower to launch (approximately 15 supernovae).
“The two bubbles appear to interact at their edges, which is where the Taurus molecular cloud is,” said study lead author Shmuel Bialy, a theoretical astrophysicist at the Center for Astrophysics. Harvard & Smithsonian, in an email to Gizmodo. The interaction of the two bubbles may be the cause of the formation of Taurus. But this requires further investigation.”
These types of bubbles have been theorized decades agoBut new technologies are able to test those theories in ways that weren’t possible before. The researchers also note that it is possible that the Milky Way is filled with such bubbles, because if they were rare, it is unlikely that our solar system would be at the center of one.
Deciphering how the bubbles interact with each other is the next step in understanding how these structures act as nurseries for stars throughout the galaxy. And with our planet at the center of one planet, we’re in a great position to learn more.