Monster star that died ... without a big bang!
A MONSTER star that mysteriously ‘vanished’ from a nearby galaxy has left astronomers baffled.
Experts at Trinity College Dublin think the ‘luminous blue variable’, which was 2.5million times brighter than our sun, may have collapsed into a black hole without first exploding as a supernova.
The researchers say it could be the first known example of a star ending its life in this way.
Located more than 70million light-years away in the constellation of Aquarius, this star is part of the Kinman Dwarf galaxy.
Scientists are not sure why the star can no longer be seen but believe there may be two explanations. The first is that the star may have become less luminous and is being partially obscured by dust, and the second, more intriguing, suggestion is that the star collapsed into a black hole without exploding as a bright supernova.
Andrew Allan, a PhD student at Trinity College Dublin, who led the research, said if the star did collapse and mysteriously vanished, ‘this would be the first direct detection of such a monster star ending its life in this manner’.
He added: ‘It would be highly unusual for such a massive star to disappear without producing a bright supernova explosion.’
The researchers used the European Southern Observatory’s Very Large Telescope (VLT), located in the Chilean Atacama
Desert, to observe the star.
At 75million light-years away, it is too far away for astronomers to see but the researchers were able to confirm the star’s presence by examining the data that revealed its unique chemical signature.
Between 2001 and 2011, scientists found evidence of a ‘luminous blue variable’ star which is 2.5million times brighter than the sun.
Luminous blue variables are unstable stars prone to giant outbursts over the course of their lives. However, in 2019, the astronomers could no longer find the telltale signatures of the star.
Jose Groh, also of TCD, and one of the study authors, said: ‘We may have detected one of the most massive stars of the local universe going gently into the night.’
The researchers said further studies are needed to understand what happened. The findings are published in the Monthly Notices of the Royal Astronomical Society.
It is 2.5m times brighter than sun