A dense star-birth engine in a nearby galaxy may be fueled by a spiral of stars.
That’s according to new research conducted with the Hubble Space Telescope and the European Southern Observatory’s Very Large Telescope, targeting a dense cluster of stars in the Small Magellanic Cloud, a dwarf galaxy relatively close to our own Milky Way Galaxy. The researchers found that the outer spiral arm of stars, gas and stars in a massive cluster known as NGC 346 appears to spiral toward the center of the cluster, fueling the birth of newborn stars there.
The findings were published Thursday in The astrophysics magazine.
“A spiral is really the good, natural way to feed star formation from the outside to the center of the cluster,” Peter Zeidler, a postdoctoral researcher at the Space Telescope Science Institute (STSci) in Baltimore, and one of the researchers behind the study , said in a statement, “It’s the most efficient way for stars and gas that fuel more star formation to move toward the center.”
This efficient fuel supply could explain why NGC 346 spawns so many young stars. Although the cluster is only 150 light-years in diameter – the Milky Way, on the other hand, is 100,000 light-years in diameter – it is as massive as 50,000 suns.
STSci star-forming scientist Elena Sabbi led the study, in which the Very Large Telescope and Hubble tracked stars in the spiral arm of NGC 346 for 11 years, allowing researchers to discover their inward spiral motion. They found that the stars move an average of 2,000 miles per hour, about 200 million miles — or about twice the distance from Earth to the sun — in 11 years.
Astronomers like to study star formation in the Small Magellanic Cloud, in part because its chemistry resembles that of the very early Universe, a period about two to three billion years after the Big Bang when the cosmos was producing new stars at a fantastic rate.
“Stars are the machines that shape the universe. We wouldn’t have life without stars, and yet we don’t quite understand how they form,” Dr Sabbi said in a statement. “We have several models that make predictions, and some of these predictions are contradictory. We want to determine what regulates the process of star formation, because those are the laws we need to understand what we see in the early universe as well.”
Although the Small Magellanic Cloud is relatively close to the Milky Way on an intergalactic scale, it is still 200,000 light-years from Earth. To more accurately measure the motions of the stars in the spiral, scientists plan to use additional Hubble observations, along with observations from the newly operational James Webb Space Telescope, which should be able to capture images of stars with lower stars. mass than Hubble to solve.