Supernova radioisotopes show sun was born in star cluster

Oct 04, 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: Novel method for identifying rings around extrasolar planets

add to favorites email to friend print save as pdf

Related Stories

Hunting transiting exoplanets

21 hours ago

European Southern Observatory (ESO) gears up for the exoplanet hunting. The Next-Generation Transit Survey (NGTS), a wide-field observing system made up of an array of twelve telescopes was installed at ESO's ...

Where do stars form in merging galaxies?

20 hours ago

Collisions between galaxies, and even less dramatic gravitational encounters between them, are recognized as triggering star formation. Observations of luminous galaxies, powered by starbursts, are consistent ...

Giant methane storms on Uranus

18 hours ago

Most of the times we have looked at Uranus, it has seemed to be a relatively calm place. Well, yes its atmosphere is the coldest place in the solar system. But, when we picture the seventh planet in our ...

Could the Milky Way become a quasar?

Feb 27, 2015

A quasar is what you get when a supermassive black hole is actively feeding on material at the core of a galaxy. The region around the black hole gets really hot and blasts out radiation that we can see billions ...

Recommended for you

Planet 'reared' by four parent stars

15 hours ago

Growing up as a planet with more than one parent star has its challenges. Though the planets in our solar system circle just one star—our sun—other more distant planets, called exoplanets, can be reared ...

Far from home: Wayward cluster is both tiny and distant

Mar 03, 2015

Like the lost little puppy that wanders too far from home, astronomers have found an unusually small and distant group of stars that seems oddly out of place. The cluster, made of only a handful of stars, ...

User comments : 0

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.