In the search for subatomic clues that shed light on the origins of our galaxy, a new study at that National Superconducting Cyclotron Laboratory at Michigan State University is examining microscopic dust particles that likely stem from stellar explosions that took place prior to the creation of the sun. The team that headed the study seeks to determine whether these microscopic particles, which were found in meteoritic material on Earth, came from classical novae explosions.
Classical novae are thermonuclear explosions that take place on small stars that are part of a binary star system, which is when two stars are orbiting each other. These types of explosions likely lead to the ejection of stellar material - such as gas and dust - into the interstellar space between stars in the galaxy, some of which likely wound up being used in the creation of our solar system.
"There is a recycling process going on here," said Christopher Wrede, spokesperson for the experiment. "When stars die, they spew out material in the form of dust and gas, which then gets recycled into future generations of stars and planets."
Wrede and his team created and studied the radioactive nuclei that are known to have the largest influence on silicon isotope production in novae. They discovered that grains of stardust typically contain high amounts of the silicon-30 isotope, which is quite rare on Earth.
Although scientists already know that this isotope is create in classical novae, little is known about the nuclear reaction rates in the explosion, meaning the nature of the silicon-30 creation process is hazy. Wrede and his team change that by discovering a new nuclear reaction path using computer models of the explosion, which will now be used to identify the dust grains.
"These particular grains are potential messengers from classical novae that allow us to study these events in an unconventional way," Wrede said. "Normally what you would do is point your telescope at a nova and look at the light."
"But if you can actually hold a piece of the star in your hand and study it in detail, that opens a whole new window on these types of stellar explosions," he concluded.
The findings were published in the March 8 issue of Physical Review Letters.
