Vast bubble in interstellar space source of all nearby, young stars

Wed, 12 Jan 2022 22:42:12 GMT
Space Daily

Boston MA (SPX) Jan 13, 2022 The Earth sits in a 1,000-light-year-wide void surrounded by thousands...

The Earth sits in a 1,000-light-year-wide void surrounded by thousands of young stars - but how did those stars form?

"This is really an origin story; for the first time we can explain how all nearby star formation began," says astronomer and data visualization expert Catherine Zucker who completed the work during a fellowship at the CfA. The paper's central figure, a 3D spacetime animation, reveals that all young stars and star-forming regions - within 500 light years of Earth - sit on the surface of a giant bubble known as the Local Bubble.

The Source of Our Stars: The Local Bubble Using a trove of new data and data science techniques, the spacetime animation shows how a series of supernovae that first went off 14 million years ago, pushed interstellar gas outwards, creating a bubble-like structure with a surface that's ripe for star formation.

Today, seven well-known star-forming regions or molecular clouds - dense regions in space where stars can form - sit on the surface of the bubble.

"We've calculated that about 15 supernovae have gone off over millions of years to form the Local Bubble that we see today," says Zucker who is now a NASA Hubble Fellow at STScI. The oddly-shaped bubble is not dormant and continues to slowly grow, the astronomers note.

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

Bubbles Everywhere? "When the first supernovae that created the Local Bubble went off, our Sun was far away from the action," says co-author Joao Alves, a professor at the University of Vienna.

Today, as humans peer out into space from near the Sun, they have a front row seat to the process of star formation occurring all around on the bubble's surface.

Charting out bubbles, and their relationship to each other, will ultimately allow astronomers to understand the role played by dying stars in giving birth to new ones, and in the structure and evolution of galaxies like the Milky Way.

Zucker wonders, "Where do these bubbles touch? How do they interact with each other? How do superbubbles drive the birth of stars like our Sun in the Milky Way?".

Summarized by 65%, original article size 2261 characters