Biggest Binary Star System Ever Discovered

Astronomers were able to observe for the first time the properties of a giant binary system consisting of the most massive stars ever found. The giant binary system is located 20,000 light years away near the centre of the Milky Way and consists of two extremely massive stars orbiting each other.

The strange thing about the duo is the fact that the bigger of the two stars is 114 times as massive as the Sun, so big that according to some astronomers it shouldn't exist, since it should have blown itself to pieces.

Anthony Moffat of the University of Montreal led the team that made the discovery and named the two stars "A1" and said that this is actually the first time a star is found to exceed the landmark 100 times the mass of our Sun, beyond which it was not really supposed to exist.

This is not the first binary system astronomers found, but only a handful of them are thought to have around 100 times the mass of the Sun. Another pair of stars, discovered not long ago and named LH54-425 is made up of the brightest stars ever found, but the largest contains about 62 times the mass of our Sun.

Actually measuring the weight of a star is possible because the two stars, in star cluster NGC 3603, are in orbit around each other, making it easy for scientists to observe the stretching and squashing of light, due to the Doppler effect, as the stars race around each other through space, completing one orbit every 3.8 days.

This is exactly what they did, using the Doppler data from the European Southern Observatory's Very Large Telescope (VLT) in Chile. Once they knew the speed of the stars and the distance between them it was easy to calculate how great their masses must be in order for gravity to keep them in that orbit.