Sun Was a Late 'Boomer' to the Milky Way

Billions of years ago, the Milky Way galaxy was churning out stars at an amazing rate, in what scientists are calling a stellar "baby boom." Now new research shows that our own Sun was a late "boomer" to the party.

The Milky Way's star-birthing frenzy peaked 10 billion years ago, but the Sun didn't form until roughly 5 billion years ago. By that time, the star formation rate in our galaxy had plunged to a trickle.

However, according to the new findings, published in The Astrophysical Journal, that may not have been such a bad thing. The Sun's late arrival may have actually promoted the growth of our solar system's planets.

As more massive stars ended their lives early, their deaths enriched the galaxy with elements heavier than hydrogen and helium - materials that were the building blocks of planets such as Earth.

In order to better understand the beginning of our solar system, the researchers studied galaxies similar in mass to our Milky Way, found in deep surveys of the Universe. From those surveys, stretching back in time more than 10 billion years, they were able to create a series of images containing nearly 2,000 snapshots of Milky Way-like galaxies.

That's because, as we all know, starlight from long ago is just arriving at Earth now. So the farther into the Universe astronomers look, the further back in time they can see.

What they found was that during the stellar "baby boom," the Milky Way was forming stars at a rate about 30 times faster than today.

"This study allows us to see what the Milky Way may have looked like in the past," Casey Papovich of Texas A&M University in College Station, the study's lead author, said in a news release. "It shows that these galaxies underwent a big change in the mass of its stars over the past 10 billion years, bulking up by a factor of 10, which confirms theories about their growth. And most of that stellar-mass growth happened within the first 5 billion years of their birth."

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