Stellar Nursery Reveals Details About Birth of the Sun
A stellar nursery that produced our solar system formed 30 million years before the birth of the Sun, revealing details about the events leading up to the Sun's debut, according to a new study.
Researchers used radioactivity to date the last time that heavy elements such as gold, silver, platinum, lead and rare-earth elements were added to the solar system matter by the stars that produced them.
"Using heavy radioactive nuclei found in meteorites to time these final additions, we have got a clearer understanding of the prehistory of the solar system," Dr. Maria Lugaro, with Monash University in Australia, said in a press release.
Lugaro and colleagues calculated that the last time elements such as lead were added into the solar system's birthing materials was no more than 30 million years before formation of the Sun.
"This timing is significant because it represents the maximum time that the solar system matter was isolated from the rest of the galaxy - and hence could not experience any more addition - inside a stellar nursery before the formation of the Sun," Lugaro told Discovery News.
The study settles a long-standing discrepancy between the abundances of two radioactive isotopes - iodine-129 and hafnium-182 - at the time the Sun was born some 4.5 billion years ago. The samples came from meteorites and were previously analyzed in laboratories.
"We did not measure these nuclei in meteorites, but explained the data already available," Lugaro told Discovery.
"The new research "delivers the first successful interpretation of meteoritic data that were presented beforehand but were difficult to explain," she added.
Ultimately, the researchers studied these isotopes with the goal of better understanding the circumstances surrounding the birth of the Sun and the prehistory of the solar system.
"Understanding the timescales and processes leading to the formation of our solar system is key to relate its birth environment with that of other planetary systems in the galaxy," Lugaro concluded in the press release.
The research team now plans to look at other heavy radioactive nuclei to determine the timing of the solar system's prehistory more accurately.
The study findings were published in the journal Science.