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Catalogue and alternative designations NGC 6357, Lobster Nebula


Type Emission nebula 
Position 17 24.6, -34 10
Constellation Scorpius
Camera and Telescope STXL16200 and 36.8cm RCOS Ritchey Chretien
Focal Ratio F9
Exposure Details This is a LSIIHaOIII image with Luminance = 165 minutes, Sulphur II = 300 minutes, Hydrogen Alpha = 180 minutes and Oxygen III = 270 minutes using Astrodon 3nm filters


Description For reasons unknown, NGC 6357 is forming some of the most massive stars ever discovered. One such massive star, near the center of NGC 6357, is framed above carving out its own interstellar castle with its energetic light from surrounding gas and dust. In the greater nebula, the intricate patterns are caused by complex interactions between interstellar winds, radiation pressures, magnetic fields, and gravity. The overall glow of the nebula results from the emission of light from  ionized hydrogen. Near the more obvious Cat's Paw nebula, NGC 6357 houses the open star cluster Pismis 24, home to many of these tremendously bright and blue stars. The central part of NGC 6357 shown spans about 10 light years and lies about 8,000 light years away toward the constellation of Scorpius.  (Description taken from APOD)