SBIG ST8300M, Astrodon filters: RGB E-Series GenII
Ha(HaR)GBL Total 4:00 hours = Ha 90 min. [18x5 min] L 90 min. [18x5 min]+ R,G,B [4x5 min. each]
2.8-8 CF (Carbon Fiber) Powernewt OTA
Fornax mount, guided
This image is 2736x2228 pixels
Massive stars lie within NGC 6357, the central part of which is shown in the very middle of this image. That central region spans about 10 light years and the whole expansive complex lies about 8,000 light years away in the tail of the constellation Scorpius.
In fact, positioned just below center in this view of NGC 6357, star cluster Pismis 24 includes some of the most massive stars known in the galaxy, stars with over 100 times the mass of the Sun. The nebula's bright central region also contains dusty pillars of molecular gas, likely hiding massive protostars from the prying eyes of optical instruments. 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 gas (ref. http://apod.nasa.gov/apod/ap081009.html; http://apod.nasa.gov/apod/ap101121.html).
The unusual name of “War and Peace” was given to this nebula not because of the famous novel by Tolstoy, but was given to this object by scientists working on the Midcourse Space Experiment (see: http://en.wikipedia.org/wiki/Midcourse_Space_Experiment). They noted that the bright, western part of the nebula resembled a dove, while the eastern part looked like a skull in their infrared images. Unfortunately this effect cannot be seen in the visible-light image presented here. The object is also occasionally nicknamed the Lobster Nebula (ref. http://asterisk.apod.com/viewtopic.php?f=29&t=28928).
NGC 6357 was first recorded visually by John Herschel from South Africa in 1837. He only recorded the brightest central parts and the full scale of this huge nebula was only seen in photographs much later.