A mysterious arc of light found behind a distant cluster of galaxies has turned out to be the biggest, brightest and hottest star-forming region ever seen in space. The so-called Lynx Arc is one million times brighter than the well-known Orion Nebula, a nearby prototypical 'starbirth' region visible with small telescopes. The newly identified super-cluster contains a million blue-white stars that are twice as hot as similar stars in our Milky Way galaxy.
(Picture: Nasa, ESA, and The Hubble Heritage Team STScI/AURA) The Carina Nebula is a cloud of dust, hydrogen, helium and other gases around 7,500 light years away from Earth. In this picture the oxygen is blue, hydrogen and nitrogen are green and sulphur red.