Supernova radioisotopes show sun was born in star cluster

October 4, 2006

The death of a massive nearby star billions of years ago offers evidence the sun was born in a star cluster, say astronomers at the University of Illinois at Urbana-Champaign. Rather than being an only child, the sun could have hundreds or thousands of celestial siblings, now dispersed across the heavens.

In a paper accepted for publication in the Astrophysical Journal, astronomy professors Leslie W. Looney and Brian D. Fields, and undergraduate student John J. Tobin take a close look at short-lived radioactive isotopes once present in primitive meteorites. The researchers' conclusions could reshape current theories on how, when and where planets form around stars.

Short-lived radioactive isotopes are created when massive stars end their lives in spectacular explosions called supernovas. Blown outward, bits of this radioactive material mix with nebular gas and dust in the process of condensing into stars and planets. When the solar system was forming, some of this material hardened into rocks and later fell to Earth as meteorites.

The radioisotopes have long since vanished from meteorites found on Earth, but they left their signatures in daughter species. By examining the abundances of those daughter species, the researchers could calculate how far away the supernova was, in both distance and time.

"The supernova was stunningly close; much closer to the sun than any star is today," Fields said. "Our solar system was still in the process of forming when the supernova occurred."

The massive star that exploded was formed in a group or cluster of stars with perhaps hundreds, or even thousands, of low-mass stars like the sun, Fields said. Because the stars were not gravitationally bound to one another, the sun's siblings wandered away millennia ago.

Our solar system, rather than being the exception, could be the rule, the astronomers said. Planetary system formation should be understood in this context.

"We know that the majority of stars in our galaxy were born in star clusters," Looney said. "Now we also know that the newborn solar system not only arose in such a cluster, but also survived the impact of an exploding star. This suggests that planetary systems are impressively rugged, and may be common even in the most tumultuous stellar nurseries."

Source: University of Illinois at Urbana-Champaign

Explore further: Why the sun is setting on the Boeing 747

Related Stories

Why the sun is setting on the Boeing 747

February 1, 2016

It's difficult to imagine now, in the age of mass global travel, that building an aeroplane to carry hundreds of people at a time was once seen as a huge risk. But as the world's first wide-body airliner, the Boeing 747 went ...

Understanding the magnetic sun

January 29, 2016

The surface of the sun writhes and dances. Far from the still, whitish-yellow disk it appears to be from the ground, the sun sports twisting, towering loops and swirling cyclones that reach into the solar upper atmosphere, ...

Did the Vikings use crystal 'sunstones' to discover America?

February 1, 2016

Ancient records tell us that the intrepid Viking seafarers who discovered Iceland, Greenland and eventually North America navigated using landmarks, birds and whales, and little else. There's little doubt that Viking sailors ...

Giant gas cloud boomeranging back into Milky Way

January 28, 2016

Since astronomers discovered the Smith Cloud, a giant gas cloud plummeting toward the Milky Way, they have been unable to determine its composition, which would hold clues as to its origin. University of Notre Dame astrophysicist ...

Recommended for you

How friendly is Enceladus' ocean to life?

February 5, 2016

How acidic is the ocean on Saturn's icy moon Enceladus? It's a fundamental question to understanding if this geyser-spouting moon could support life.

Inside Rosetta's comet

February 4, 2016

There are no large caverns inside Comet 67P/Churyumov-Gerasimenko. ESA's Rosetta mission has made measurements that clearly demonstrate this, solving a long-standing mystery.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.