Astronomy Picture of the Day

Explanation: Star cluster RCW38 was hiding. This open cluster of stars is located about 5000 light years away towards the constellation of Vela. Looking there will not normally reveal most of the stars in this cluster, though. The reason is that the open cluster is so young that it is still shrouded in thick dust that absorbs visible light. This dust typically accompanies the gas that condenses to form young stars. When viewed in infrared light, however, the star cluster in RCW38 is revealed, because dust is less effective at absorbing infrared light. The above photograph was one of the first ever taken with the new Infrared Spectrometer and Array Camera (ISAAC) affixed to the 8.2-metre Very Large Telescope.