The War and Peace Nebula (also known as NGC 6357 and Sh2-11) is a large diffuse emission nebula about 400 light-years across where new stars are being born in of chaotic clouds of gas and dust, located about 8,000 light-years away in the constellation Scorpius, near the Cat’s Paw Nebula (NGC 6334).
The name was given by astronomers because of its appearance in the mid-infrared: in infrared images the bright, northwestern part resembles a dove, while the eastern part looks like a human skull. Unfortunately this effect cannot be seen in visible-light.
NGC 6357 includes the open cluster Pismis 24, which is home to several massive stars. One of the brightest stars in the cluster, Pismis 24-1, was thought possibly to be the most massive on record, approaching 300 solar masses, until it was discovered to be a binary system with each star exceeding 100 solar masses.
Part of the nebula is ionised by the youngest and bluest heavy stars in Pismis 24. The intense ultraviolet radiation from the blazing stars heats the gas surrounding the cluster and creates a bubble in NGC 6357.
The nebula’s bright central region also contains a river of dust, and dusty pillars of molecular gas, likely hiding many massive protostars, and young stars wrapped in expanding “cocoons”. Intricate shapes in the nebula are carved by interstellar winds and energetic radiation from the young and newly forming massive stars.