A team of astronomers led by Paul Crowther, Professor of Astrophysics at the University of Sheffield, has used ESO’s Very Large Telescope (VLT), as well as archival data from the NASA/ESA Hubble Space Telescope, to study two young clusters of stars, NGC 3603 and RMC 136a in detail. NGC 3603 is a cosmic factory where stars form frantically from the nebula’s extended clouds of gas and dust, located 22 000 light-years away from the Sun (eso1005). www.eso.org
Using a combination of instruments on ESO’s Very Large 
Telescope, astronomers have discovered the most massive stars to date, 
some weighing at birth more than 300 times the mass of the Sun, or twice
 as much as the currently accepted limit of 150 solar masses. This 
artist's impression shows the relative sizes of young stars, from the 
smallest “red dwarfs”, weighing in at about 0.1 solar masses, through 
low mass “yellow dwarfs” such as the Sun, to massive “blue dwarf” stars 
weighing eight times more than the Sun, as well as the 300 solar mass 
star named R136a1.