Astronomers have discovered "monster" stars - whose size and brightness exceed what many scientists thought was possible.
Found within two young star clusters, NGC 3603 and RMC 136a, the stars weigh up to 300 times the mass of the Sun, a figure which doubles the previously accepted limit of solar mass.
A researcher at the University of Sheffield discovered the monster stars using the European Southern Observatory's (ESO) Very Large Telescope.
The biggest star found, R136a1 within the R136a cluster, has a current mass of 265 solar masses, and it is thought its birthweight was as much as 320 times that of the Sun.
It is also the most luminous star ever found, close to ten million times that of the Sun.
If R136a1 replaced the Sun at the centre of our solar system, it would outshine our star by as much as the Sun currently outshines the Moon.
Due to the short lives of these very rare, high mass stars, it remained a challenge for astronomers to identify how they originated.