Astronomers detect massive star’s mysterious rejuvenation
In a surprising turn of events, astronomers have reported that RW Cephei, a hypergiant star in the constellation Cepheus, has suddenly begun brightening after experiencing a dramatic two-year dimming period. This revelation was made by Narsireddy Anugu, a staff scientist at the CHARA Array in California.
Anugu and an international team of astronomers have published their findings in a study released in The Astronomical Journal, proposing that the star’s unusual behavior may be attributed to a previously ejected gas cloud that cooled as it moved further away, blocking the star’s light from our view and causing it to appear fainter.
These recent observations are reminiscent of the mysterious dimming of Betelgeuse, a well-studied red supergiant that grew unexpectedly fainter in 2019. RW Cephei, on the other hand, is significantly larger and brighter, being 1,000 times bigger than our sun. Despite its colossal size, the star is so distant that it appears a million times smaller than a full moon in our sky.
During a press briefing at the American Astronomical Society conference, Anugu presented close-up images of the star captured by the CHARA array, revealing its irregular and blotchy appearance, caused by dark and bright patches across its surface due to the orbiting gas cloud.
Subsequent observations indicated that the star dimmed more sharply in visible colors compared to infrared, suggesting that the starlight was obscured by microscopic dust clouds.
Douglas Gies, director of the CHARA array, expressed that the detected gas cloud circling the star could be one of many “grand eruptions” from RW Cephei, causing the star to lose chunks of its mass.
“This one was special because the cloud was ejected in the direction of Earth, so we were in the right place to witness the full effects of the cataclysm,” said Gies.
The discovery of RW Cephei’s unusual behavior has captured the attention of astronomers and continues to provide valuable insights into the dynamic and enigmatic nature of stars in our universe.