Messier 20 (catalogued also as NGC 6514, called Trifid Nebula) is an H II region in constellation Sagittarius. Its name means 'divided into three lobes'. This is an unusual combination of an open cluster of stars; an emission nebula (the right, red portion), a reflection nebula (the left, blue portion) and a dark nebula (catalogued as Barnard 85 which represents the apparent 'gaps' within the emission nebula that cause the trifid appearance).