Astronomers using NASA’s Chandra X-ray Observatory say they have identified the trigger behind repeated outbursts from AT 2016blu, a giant and unstable star in the spiral galaxy NGC 4559. A new image of the galaxy was released on Nov. 9, 2026.
NGC 4559 lies about 30 million light-years from Earth. Astronomers estimate that AT 2016blu has a mass at least 33 times that of the Sun. The star is described as volatile because it has gone through repeated eruptions rather than a single event.
The image combines X-ray data from Chandra with optical data from the Sloan Digital Sky Survey (SDSS). The X-ray component is credited to NASA, the Chandra X-ray Center, the University of Virginia, and M. Aghakhanloo and colleagues. Image processing was done by P. Edmonds of the Smithsonian Astrophysical Observatory, working with the Chandra X-ray Center.
The material supplied with the release does not describe the mechanism that triggers the outbursts, and the underlying study is not detailed here. The full findings are covered in the accompanying NASA discovery report.
Chandra observes the high-energy X-ray emission that can accompany violent activity around massive stars. For a star as massive as AT 2016blu, that capability gives astronomers a way to study its erratic behavior at wavelengths that optical telescopes alone cannot capture.
Source: www.nasa.gov
