Subaru Telescope detects possible 1st-generation star


Scientists using Hawaii Island’s Subaru Telescope detected a star that’s providing evidence to back up theories and simulations about the existence of very massive stars after the universe’s creation.

Those very massive stars, known as first-generation stars, would likely have had a low metal content and lots of helium and hydrogen gases, Subaru Public Information Officer Suzanne Frayser said.

Ideas about the first generational stars came about from questions such as “what was the universe like after the Big Bang,” Frayser said. “There have been simulations, but (until now), there’s nothing that supported the existence of very massive stars.”

The simulations showed what chemicals would remain after the explosion of such a massive star, leaving an unusual signature the astronomers and scientists then found in a low-mass star, labeled SDSS J0018-0939. The signature showed the low-mass star preserved the proportion of elements from the first generational star, the first observational evidence to back up the simulations about those first-generation stars. Specifically, the star had 300 times less iron than the sun, and was “significantly deficient” in lighter elements, such as carbon and magnesium, Subaru officials said.

“The extremely low abundances of elements other than iron indicates that this star formed directly from a hydrogen gas cloud that contained elements dispersed by a first-generation massive star,” a news release said.

That information opens the door for more research and new questions, Frayser said. In particular, scientists now can begin looking even more closely for information about what the makeup of those early stars was.

“It’s like it has the first clues for what was going on in the past,” Frayser said. “People had thought it was there, but they couldn’t prove it.”

First-generation stars are objects formed in the early universe, within a few hundred million years after the Big Bang, the news release said.

Scientists think the Big Bang happened 13.8 billion years ago. Lead author on the project, Wako Aoki, told Space.com Thursday he thinks the star being studied could have been as much as 13 billion years old.

Aoki, who is based in Japan, did not immediately respond to an email interview request.

“First-generation stars probably preceded the formation of the structure of the universe structure and its chemical enrichment; large stellar systems, e.g., galaxies, formed later,” the release said. “The large majority of first stars probably formed with masses of 10-100 that of the sun. Recent numerical simulations suggest that a small fraction of very-massive stars with masses exceeding 100 times that of the sun could have formed in the early universe.”

Email Erin Miller at emiller@westhawaiitoday.com.

 

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