They discover that the Earth is inside a huge bubble that created the nearby stars

14 million years ago, a series of events led to the creation of a large bubble that is responsible for the formation of all the young stars close to Earth, according to a study published by Nature this Wednesday, January 12.

This is the first time that a group of scientists, led by the Harvard and Smithsonian Center for Astrophysics (CfA), explain how the upcoming star formation began, using simulations, new techniques and data.

The study is based on a 3D space-time animation, which reveals that all young stars and star-forming regions, within 500 light-years of Earth, are on the surface of a giant structure known as the Local Bubble.

Astronomers have known about it for decades, but now the beginnings of that bubble and its impact on the gas around it can be seen and understood.

The space-time animation shows how a series of supernovae that erupted 14 million years ago pushed interstellar gas outward. Then, a bubble-shaped structure was created with a surface ripe for star formation.

Today, seven well-known star-forming regions or molecular clouds – dense areas in space where stars can form – lie on its surface.

“We have calculated that some 15 supernovae have exploded over millions of years to form the Local Bubble that we see today,” said Catherine Zucker, who completed the work while at the CfA.

The bubble is not inactive and continues to increase in volume slowly, at about six kilometers per second, but “it has lost most of its momentum and has stabilized in terms of speed,” according to the expert.

The speed of expansion of the bubble, as well as the past and present trajectories of young stars forming on its surface, were deduced using data obtained by Gaia, a space observatory launched by the European Space Agency (ESA).

With the new system, the history of the star formation around us can be reconstructed, “using a wide variety of independent clues: supernova models, stellar movements and new and exquisite 3D maps of the material that surrounds the Local Bubble”, detailed another of the authors, Alyssa Goodman, Harvard University.

When the first supernovae erupted creating the Local Bubble, “our Sun was a long way from the action,” added co-author João Alves, a professor at the University of Vienna.

However, about five million years ago, the Sun’s path through the galaxy took it right inside the bubble, and it is, “just luckily, almost right in the center” of it.

Astronomers first proposed that superbubbles were ubiquitous in the Milky Way nearly fifty years ago and “now we have evidence,” Goodman said.

Tracing the bubbles and the relationship between them will allow astronomers to understand the role that dying stars play in the birth of new ones and in the structure and evolution of galaxies like the Milky Way.

With information from EFE.