NGC 6357 is an emission nebula located in the constellation Scorpius. This region, well known as a fast paced star birth one, hosts many very massive and luminous stars. Its central open cluster (Pismis 24) hosts at least 20 stars with masses above 10 solar masses, with some above 100 solar masses. It has another nickname: “War and Peace” Nebula, because, seen in infrared light, the western part resembles a dove, while its eastern one looks like a skull.
Divertimento: As a matter of curiosity, in 2012, a group of people filed a petition to the International Astronomical Union to change its name to “Madokami Nebula“, due to its alleged similarity to this japanese comic character… The petition fell short of the requested 25,000 supporters needed to open the discussion…
This image was taken is narrowband (with RGB stars, as usual) and combined in both the natural color as well as mapping the filters to the Hubble Color Palette. This time, and as an exception for me, I like the HCP combination better.
The superluminance (Ha+OIII+SII) of this image has been used to enhance the resolution of the wide field image of NGC 6357 + NGC 6334 that can be seen here.
Name(s): NGC 6357. The Lobster Nebula
Type: Emission Nebula
RA: 17h 25m 02s
Dec: -34º 12’ 17”
Size (arcmin): 50 x 40
Distance: 8000 ly
Date: 2017-04-30 thru 2017-07-10
Location: iTelescope.net, SSO near Coonabarabran, NSW Australia
Size (arcmin): 37 x 37
Telescope: Planewave CDK 20” f/6.8
Camera: SBIG STX16803 (4096x4096pix)
Guiding: Astrodon MonsterMOAG off-axis guider
Total exposure: 25.5 hours (Ha: 11h 30m; OIII: 8 h; SII: 4h 30m; RGB: 1h 30m)
Processing: CCDStack, Photoshop CC 2018