Astronomy Picture of the Day . The Trifid Nebula is Stars and Dust . ... 28.07.2010 . ... Also known as M20, this photogenic nebula is visible with good binoculars towards the constellation of Sagittarius . ... The dark dust filaments that lace M20 were created in the atmospheres of cool giant stars and in the debris from supernovae explosions. Which bright young stars light up the blue reflection nebula is still being investigated . ... Publications with keywords: Trifid nebula - M 20 . ...