Messier 20, also known as the Trifid Nebula, is an H II region in the constellation Sagittarius around 4,100 light-years from Earth.

Discovered by Charles Messier on June 5, 1764 its name means 'three-lobe'.

The object is an unusual combination of an open cluster of stars, an emission nebula, a reflection nebula and a dark nebula.

The most massive star that has formed in this region is HD 164492A, an O7.5III star with a mass more than 20 times the mass of the Sun. This star is surrounded by a cluster of approximately 3,100 young stars.

Location: El Sauce Observatory, Río Hurtado, Coquimbo Region, Chile
Data Source: Telescope Live