With a mass equivalent to 256 times that of our Sun, thestarR136a1, located in the clusterR136, it istwice the size of anything ever seen before. In addition, it is not only the most massive detected, but it is alsothe brightest, about ten million times more than the Sun. This stellar “heavyweight” has been observed thanks to a combination of instruments from theVery Large Telescopeof the European Southern Observatory (ESO).
“The existence of these ‘monsters’, millions of times brighter than the Sun, which lose weight through very powerful winds, could provide an answer to the question of how massive stars can be,” explained Paul Crowther, professor. of Astrophysics at the University of Sheffield and head of the group of scientists who made the discovery.
“Unlike humans,these stars are born heavy and lose weight with age. Being a little over a million years old, the most extreme star,R136a1, is in a ‘middle age’ and has suffered an intense weight loss, shedding in that time a fifth of its initial mass or more than 50 solar masses “, adds Crowther. These heavy stars are extremely rare Yform only within the densest star clusters. AndR136a1If it would replace the Sun in the Solar System, astronomers explain, its high mass would reduce Earth’s year length to three weeks and bathe Earth in incredibly intense ultraviolet radiation, making life on our planet impossible.
Distinguishing individual stars, as has now been accomplished for the first time, requires the special resolving power of the VLT’s infrared instruments. The discovery supports the previous view that there is an upper limit that determines the maximum size of a star, although that limit has been increased to about 300 solar masses, twice what was previously thought. And according to Crowther it seems unlikely that this new record will be broken anytime soon.
Understanding how colossal stars like these are formed is quite difficult. “Either they were born as big or smaller stars merged to produce them,” explains Crowther. In fact, stars between eight and 150 solar masses explode at the end of their short lives as supernovae, leaving behind exotic remnants, such as neutron stars or black holes.
