Scientists Discover Cosmic Dust Discs that Can Stand the Heat
A team of scientists has discovered cosmic discs of dust and gas at the center of the Milky Way galaxy that can quite literally stand the heat - that is, heat emanating from millions of large, hot stars that should otherwise destroy such discs.
More young stars are born in the dark clouds at the heart of the Milky Way than in any other place in the galaxy. This stellar nursery includes clusters such as "Quintuplet" and "Arches," which contain stars as massive as 100 times the mass of the Sun. Now, astronomers at the University of Bonn have detected about 20 rotating discs in each cluster.
This comes as a surprise because it was previously believed that the intense UV radiation from the young stars would otherwise incinerate these dusty discs. However, that is not the case.
"We expected that the enormous radiative energy of these giant beasts evaporate the material around their smaller neighbors in less than one million years," researcher Dr. Andrea Stolte said in a statement.
"In such a hostile environment, we did not expect to find any circumstellar discs after more than a few hundred thousand years, and yet we found more than 20 discs in each cluster at ages of a few million years," she added.
The team observed this incredible phenomenon using the European Southern Obervatory's (ESO) Very Large Telescope (VLT) in the Chilean Atacama desert and the Hubble Space Telescope (HST). These powerful telescopes were able to capture infrared light that gave scientists a more detailed glimpse into the core of our galaxy.
So how exactly do these discs survive the hellfire of their giant neighbors? Scientists still aren't exactly sure, but they suggest that either the gas and dust discs simple boast a never-before-seen resistance to their hostile environment, or that a previously unobserved mechanism recharges the discs.
The key to the second theory may lie in the companion stars themselves. That is, when two stars circle each other, the bigger companion may provide fuel to its smaller twin, possibly refueling disc material at a rate large enough to make up for the evaporated losses caused by the intense UV radiation.
"Many unknown processes take place in these rich, young star clusters," Stolte said. "The tight interaction and mass flow between numerous close twins observed in other star-forming environments might also be the explanation for the dusty discs we found in these massive clusters."
If dense discs of gas and dust indeed can survive for extended periods of time in such extreme conditions, it may provide insight into planet formation.
The results were published in the journal Astronomy & Astrophysics.
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