This diagram shows two possible fates of a massive hot star such as R136a5. With a mass of about 60 times that of the Sun, R136a5 should exhaust its nuclear fuel and come to its end - whatever that might be - in just a few million years. The fate of this massive star may depend on the rate at which it is losing mass in its stellar wind.
If the rate of mass loss were low, R136a5 would expand and become - a red supergiant star, as shown on the left side of the diagram. Soon, the star would use up its central storehouse of nuclear fuel and then collapse into a black hole. However, it appears that a slightly less exotic fate awaits the massive star, and there is no black hole in the offing. The HST observations of R136a5 revealed that has a stellar wind so strong that gas equal in mass to our Sun is removed every 50,000 to 100,000 years. If the wind continues at that furious rate, the mass of R136a5 will be reduced so much by the time that its central nuclear fuel store has been used up, that it will explode as a typical 'Type ll' supernova. The imploding stellar core will produce a neutron star.
In the interim, it appears that the rapid mass loss from the exterior of R136a5 may form an expanding cloud of gas around the star. Physical changes in the atmosphere of the star, already underway, will lead to its classification as a so-called Wolf-Rayet star. Wolf-Rayet stars have a high surface temperature, a strong stellar wind and a particular type of peculiar spectrum.
Credit: J. Sandoval (CSC), and NASA
