Chandra Data Point to the Cause of a Star’s Repeated Outbursts

AT 2016blu is a massive star in the galaxy NGC 4559, about 30 million light-years from Earth.

It is a luminous blue variable, a rare kind of star that can undergo powerful changes in brightness.

Unlike a supernova, which is a single explosive event, AT 2016blu has flared roughly every 113 days.

Astronomers classify it as a supernova impostor because it brightens like an exploding star but is expected to survive.

Researchers used observations from NASA’s Chandra X-ray Observatory to investigate the repeated flares.

They propose that a compact companion triggers the outbursts as it passes close to the star in an elongated orbit.

The finding offers a possible explanation for the star’s unusual pattern, but the proposed binary system is not described as confirmed.