... Where are the hot stars in M81, one of the closest major spiral galaxies? ... HD 189733b is a Jupiter-sized planet known to orbit a star some 63 light-years away. ... LDN 1622: Dark Nebula in Orion . ... In the center of star-forming region 30 Doradus lies a huge cluster of the largest, hottest, most massive stars known. These stars, known as the star cluster R136, and part of the surrounding nebula are captured here in this gorgeous visible-light image from the Hubble Space Telescope. ...