THis is a closer view of the big one - NGC3603 is much larger and much further away. The cluster at the centre of NGC3603 is one of the most massive in the Milky Way, containing truly massive stars. One is nearly 3 million times more luminous than the Sun, and 132 times the mass. NGC3603 is reddened by intervening dust, hinting that it is much further away than NGC3576, it's some 22,500 light-years distant.