NGC 6357, also commonly known as the Lobster Nebula, is located in the constellation Scorpius approximately 5,500 to 6,500 light years from the Earth. The nebula is a prolific stellar nursery. It contains many new protostars that are shielded by dark disks and cocoons of gas and dust. The nebula contains new, very hot, stars that apparently are in the process of clearing areas around them by radiation pressure and stellar winds. Located near the center of the image is the open cluster Pismis 24 which includes very massive, and possibly the most massive recorded, stars. At least two of the stars are estimated to be about 100 times the mass of our Sun.
The image above is known as a mapped, or false color, image and was acquired using narrowband filters. It was assembled using the standard Hubble Palette with SII mapped to Red, Ha mapped to Green and OIII mapped to Blue.