The Trifid Nebula or Messier 20 is an complex nebula located in Sagittarius. Its name means 'divided into three lobes'. The object is an unusual combination of an open cluster of stars, an emission nebula (the lower, red portion), a reflection nebula (the upper, blue portion) and a dark nebula, these are also designated Barnard 85. For more technical detail look in my site : http://astrofarma.gr/index.php/en/m20
Farmakopoulos Antonis