Assertion: supernova's progenitor star | /r/HasProperty | blue supergiant
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text: It has been a mystery why the progenitor star was a blue supergiant," says Masaomi Ono at the RIKEN Astrophysical Big Bang Laboratory.
text: It has been a mystery why the progenitor star was a blue supergiant," Masaomi Ono, who led the research team at RIKEN Astrophysical Big Bang Laboratory, said in a statement.