Researchers call the new star Earendel – in Old English the “morning star”. If it were a single star, astronomers estimate it would be a massive star — about 50 times the mass of our sun. It can also be a two or more star system.
The alignment of Earendel and the galaxy cluster will last for many years, so Earendel will be one of the targets for observations in the first year of the newly launched cluster. James Webb Space Telescopewhich has a mirror larger than Hubble and collects light at longer infrared wavelengths.
Webb’s observations will be able to measure brightness across the entire spectrum of wavelengths. This will help astronomers determine the temperature of the star. “We really need that spectrum to say with absolute certainty that this is a star compared to other types,” Welch said.
Mr Welch said that later, more detailed observations by Webb could determine Earendel’s composition. The Big Bang produced only the lightest elements, such as hydrogen and helium. The first stars were thus expected to contain lower concentrations of the heavier elements, which arise from fusion reactions within stars and in the explosions of dying stars. The current hypothesis is that with fewer heavier elements, the first stars should be large and bright.
“It appears to be very hot and very massive,” Stephen Finkelstein, an astronomer at the University of Texas at Austin who was not involved in the study, said of Earndale.
However, this star alone would not be sufficient to prove the state of the largest star in the early universe. “But he definitely supports that,” said Dr Finkelstein. “If you start forming a large number, and many of them appear very massive, the evidence gets even stronger that more massive stars are the norm in distant universes.”
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