The cloud that formed our solar system brewed for 30 million years before the birth of the Sun, a new study has found.
The event coincided with the death of a giant red star, says one of the study's co-authors Professor John Lattanzio of Monash University in Melbourne.
The research, reported in the journal Science, provides the most detailed timeline yet for the events that led to the creation of our solar system, and indicates the process was more complex than previously thought.
"This is gives us a good view of where we came from and what happened just before the solar system," says Lattanzio.
It is estimated that our Sun and solar system formed 4.6 billion years ago.
The current popular scenario for the birth of our solar system suggests a shockwave from an exploding supernova 4.7 billion years ago caused the collapse of a giant molecular cloud to form the Sun and solar system.
But it has been hard to pin down the pre-history of our solar system because we don't know enough about how stars produce radioactive elements.
Some radioactive elements such as hafnium 182 and iodine 129 are produced in a process called rapid neutron capture, which occurs during supernovae explosions.
To learn more about the environment in which our Sun and planets formed, Lattanzio and colleagues analysed how long it takes these radioactive elements to decay.
Their analysis shows that a supernova exploded in the vicinity about 100 million years before the birth of our Sun and solar system. But their findings also pin down a second event that has long-puzzled scientists.
Analysis of meteorites has previously found younger hafnium 182 isotopes dating to around 15 million years before the birth of the solar system, but no similarly aged 129 isotopes.
"If there was an event at 15 million years, it would have made both hafnium and iodine," says Lattanzio.
"You can't make one without the other since they come from the same process, so this was a cause of some concern." The anomaly suggests another process other than a supernova explosion was involved in the formation of our solar system.