... Nebulae For Christmas . ... If our Galaxy were a Christmas tree, planetary nebulae would adorn it like colorful lighted ornaments twinkling on a cosmic scale. Glowing shrouds of gas ejected by red giant stars, planetary nebulae like.. ... Ring Around the Galaxy . ... Cartwheel Of Fortune . ... The Cartwheel is part of a group of galaxies about 500 million light years away in the constellation Sculptor (two smaller galaxies in the group are visible on the right). ... The Night Shift . ...