The Universe Has a Lot More Huge Stars Than Scientists Thought

New observations from Chile’s Atacama Large Millimeter/submillimeter Array (ALMA) reveal that starburst galaxies, like the one in an artist’s impression above, have many more massive stars than peaceful galaxies do. Credit: M. Kornmesser/ESO
A surprisingly large number of massive stars have been spotted in regions across the universe, shedding new light on how galaxies near and far evolve, a new study shows.

By Samantha Mathewson |

In the study, astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile investigated intense bouts of star formation in four distant, gas-rich starburst galaxies, where new stars are formed 100 or more times faster than they are in our own galaxy, the Milky Way.

Massive stars in these galaxies produce outflows of gas and create supernova explosions, which release large amounts of energy and stellar material into space. This type of activity can have a significant impact on the area surrounding these stars, according to a statement from the European Southern Observatory (ESO). [Supernova Photos: Great Images of Star Explosions]

Using a new technique similar to radiocarbon dating, the researchers looked for signatures of different types of carbon monoxide to determine the mass distribution of stars in the starburst galaxies. While oxygen isotopes are associated with larger, more massive stars, carbon isotopes are associated with smaller, intermediate-mass stars, Zhi-Yu Zhang, lead researcher and astronomer from the University of Edinburgh, said in the statement. Because carbon and oxygen combine to form carbon monoxide, this means different variations of carbon monoxide form more frequently in larger stars than in smaller ones.

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