NGC 6357 is a diffuse nebula near NGC 6334 in the constellation Scorpius. The nebula contains many proto-stars shielded by dark discs of gas, and young stars wrapped in expanding "cocoons" or expanding gases surrounding these small stars. It is also known as the Lobster Nebula. This nebula was given the name War and Peace Nebula by the Midcourse Space Experiment scientists because of its appearance, which, in infrared images the bright, western part resembles a dove, while the eastern part looks like a skull.
It is located about ~5,500 light years away from Earth.
Associated open clusters
This nebula 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 multiple system of at least three stars; component stars would still remain near 100 solar masses each, making them among the more massive stars on record.
NGC 6357 is one of the most prominent sites of massive-star formation in our neighborhood of the Milky Way. A variety of early O-type stars reside in this nebula, blowing the bubbles around the star clusters that can be seen in the molecular cloud.
A new calibration of stellar parameters of Galactic O stars | Astronomy & Astrophysics (A&A)
February 20, 2013
Star formation and disk properties in Pismis 24 | Astronomy & Astrophysics (A&A)
THE MASSIVE STAR-FORMING REGIONS OMNIBUS X-RAY CATALOG - IOPscience
June 11, 2014
Zooming in on NGC 6357
June 21, 2012