(ORDO NEWS) — Earth is located inside a giant void about 1000 light-years across, surrounded by thousands of young stars – but how did these stars form?
In a new paper, astronomers led by Catherine Zucker of the Harvard-Smithsonian Center for Astrophysics, USA, recreate the evolutionary history of our galactic neighborhood, demonstrating how a chain of events that began 14 million years ago led to the formation of a huge bubble that is responsible for the formation of all nearby young stars.
The central element of the visualization underlying this work is the 3-D animation of the Earth’s cosmic neighborhood., demonstrates that all young stars and star-forming regions – located at distances less than 500 light-years from Earth – lie on the surface of a giant bubble known as the Local Bubble.
Although scientists have known about the existence of this structure for decades, only now have they managed to figure out its origin and influence on the surrounding gas.
Using new datasets and processing techniques, the researchers created a space-time animation showing how several supernovae, the first of which erupted approximately 14 million years ago, pushed the gas of the interstellar medium outward, forming a bubble-like structure on the surface of which processes of formation are intensively new stars.
Today, seven well-known star-forming regions, or molecular clouds – dense regions in space where stars can form – lie on the surface of the bubble.
“We calculated that roughly 15 supernovae erupted over millions of years to form the Local Bubble that we see today,” Zucker said.
This unusual bubble is not “sleeping” and continues to slowly grow, the astronomers noted.
“It’s growing at about 6.5 kilometers per second,” Zucker said. “Its growth rate has been declining rapidly and has now reached a relatively constant value.”
The expansion rate of the bubble, as well as the past and present trajectories of the young stars that formed on its surface, were studied using data collected using the European Space Agency’s Gaia satellite.
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