Every star ages, but astronomers rarely get to watch it happen in real time. Now, they’ve gotten a front-row seat to the aging of an unusually chaotic star — and found that it’s headed toward a spectacularly violent death.

The star, located in the nearby Triangulum galaxy (also known as Messier 33), is in the middle of a transition into a class of highly unstable stars called Wolf-Rayet stars. New observations show that the star has begun beaming a new signal that was not seen when the star was first spotted in 2018.

The new signal was detected in the peaks and valleys of the star’s spectra, the wavelengths of the electromagnetic radiation it emits, and shows that the star is churning either carbon or iron deep within it through nuclear fusion. The new signal also indicates that the massive star, easily 25 times the sun’s mass, has inched closer to its eventual fate of exploding into a spectacular supernova.

Gaunt’s team is calling the star BELLS 1, an acronym for "broad emission-lined luminous sources, the kind of wide range of emissions radiated by Wolf-Rayet stars.

According to NASA, Wolf-Rayet stars like BELLS 1 live fast and die hard, so watching one evolve is a rare and valuable opportunity for astronomers. Only 200 such stars are known to be in the Milky Way galaxy. Astronomers suspect that 1,000 or 2,000 more may be out there but are obscured by thick blankets of dust.