Far out cosmology: our sun sits in a giant bubble (Introduction)

by David Turell , Tuesday, March 01, 2022, 23:22 (996 days ago) @ David Turell

From Gaia telescope:

https://cfa.harvard.edu/news/1000-light-year-wide-bubble-surrounding-earth-source-all-n...

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

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"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. While astronomers have known of its existence for decades, scientists can now see and understand the Local Bubble's beginnings and its impact on the gas around it.

"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.

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"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.

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"'When the first supernovae that created the Local Bubble went off, our Sun was far away from the action," says co-author João Alves, a professor at the University of Vienna. "But about five million years ago, the Sun's path through the galaxy took it right into the bubble, and now the Sun sits — just by luck — almost right in the bubble's center." (my bold)

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"Astronomers first theorized that superbubbles were pervasive in the Milky Way nearly 50 years ago. "Now, we have proof — and what are the chances that we are right smack in the middle of one of these things?" asks Goodman. Statistically, it is very unlikely that the Sun would be centered in a giant bubble if such bubbles were rare in our Milky Way Galaxy, she explains." (my bold)

Comment: note this puts our sun in a very safe quiet spot away from all the dangerous activity in the galaxy. Those supernovas did not disturb evolution and were long enough ago not to harm the arrival of hominins. My bolds ask a question: Is the sun's position lucky or God's work?