This supernova impostor baffled astronomers for 15 years — until they found a hidden black hole feeding on an unstable star
A cosmic imposter that has faked being a supernova 27 times and counting is actually a hot, luminous, and decidedly unstable star that is being fed on by a vampiric black hole or neutron star, NASA’s Chandra X-ray Observatory has discovered.
Key points
- Chandra’s X-ray observations indicate that AT 2016blu has an unseen companion, a compact, high-gravity object that is either a neutron star or a stellar-mass black hole on an elliptical 113-day orbit around the luminous blue variable.
- As the stolen starstuff is dragged away from the wounded star and towards the compact object, it forms an accretion disk swirling around the neutron star or black hole so fast and growing so hot that it emits X-rays.
- Neutron stars and stellar-mass black holes are the core remnants of massive stars that have gone supernova for real, meaning that at one time AT 2016blu was a binary star system.
That’s what astronomers thought they had found on 11 January 2012, when they observed what appeared to be a supernova on the outskirts of the spiral galaxy NGC 4559, which is about 25 million light-years away in the constellation Coma Berenices.
Additional details
- These are the most massive and luminous stars in the universe and their extreme characteristics result in them being highly unstable, undergoing intermittent bouts of mass loss as they eject material from their outer layers into the surrounding space.
- Blue star falls victim to a cosmic vampire Each time the compact object reaches the point in its orbit that is closest to the luminous blue variable, its powerful gravity is able to pull material from the unstable star.
- When a massive star reaches the end of the road and runs out of nuclear fuel to power fusion reactions in its core, the star is destroyed in a supernova explosion.
- "To understand the cause of these eruptions, we realized that we needed X-ray data that was timed so that we’d observe the star when it was in an outburst," team member Núria Torres-Albà, also from the University of Virginia in Charlottesville, said.
- Thanks to Chandra ’s X-ray vision, Aghakhanloo has led a team of astronomers who think they have now uncovered an explanation.
How this summary was made: extractive summary — built from the sources' own reporting. It is drawn only from the reporting of the sources listed below — read the originals for full detail. How we summarize →
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