NGC 6357


NGC 6357 is a diffuse nebula near NGC 6334 in the constellation Scorpius. The nebula contains many proto-stars shielded by dark disks of gas, and young stars wrapped in expanding "cocoons" or expanding gases surrounding these small stars. It is also known as the Lobster Nebula and the Madokami Nebula by some fans of the anime Madoka Magica due to its resemblance to the main character from the anime and a popular fan petition to rename it.
This nebula was also 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 5500 light years away from Earth.

Associated Open Clusters

Pismis 24

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.

G353.2+0.7

The young stellar cluster G353.2+0.7 lies east of Pismis 24 and was revealed by a Chandra X-ray image showing approximately 800 stars.

G353.1+0.6

The young stellar cluster G353.1+0.6 lies southeast of Pismis 24 and also contains approximately 800 stars detected by X-ray. The region includes several O-type stars, including 10.

Massive stars

NGC 6357 is one of the most prominent sites of massive-star formation our neighborhood of the Milky Way. A variety of early O-type stars reside in this nebula, blowing the bubbles around the stars clusters that can be seen in the molecular cloud.
Star
Spectral typeMagnitude
Temperature
Radius
Mass
1NEO3.5 If*−10.042,0001774
1SWO4 III−9.841,5001666
2O5.5 V−8.940,0001243
3O8 V−7.733,400925
10O9 V−7.231,500820
12B1 V−5.330,000411
13O6.5 III)−8.635,6001235
15O8 V−7.833,4001025
16O7.5 V−9.034,0001638
17O3.5 III−10.142,7001778
18B0.5 V−6.430,000615
19B0.5 V−5.430,000411