Sh 2-11
Also called
RCW 131, Gum 66Coordinates: (353.19°, 0.84°)
[ Catalog | Explorer | SIMBAD ]
The HII region NGC 6357, also called W 22 or the War and Peace Nebula, is ionised by the Pismis 24 and AH03 J1725−34.4 star clusters. Pismis 24 includes the multiple O4 and O4-5 star system [N78] 35 according to a 1984 paper. (SIMBAD gives a cooler O7 III class for this star.)
Near by is the Wolf-Rayet star WR 93, which is also a multiple star system with a class O7-9 companion.
The Cat's Paw nebula NGC 6334 lies at approximately the same distance and is separated from it by a dark cloud. You can see both nebulae together in this image.
An amazing closeup of part of this nebula can be seen in this Hubble image.
Near by is the Wolf-Rayet star WR 93, which is also a multiple star system with a class O7-9 companion.
The Cat's Paw nebula NGC 6334 lies at approximately the same distance and is separated from it by a dark cloud. You can see both nebulae together in this image.
An amazing closeup of part of this nebula can be seen in this Hubble image.
Contains the star cluster Pismis 24 which includes a multiple O4 and O4-5 star system. Near by is the Wolf-Rayet star WR 93, which is also a multiple star system with a class O7-9 companion.[1]
At the same distance as NGC 6334 and separated from it by a dark cloud.[2]
The RCW catalog divides NGC 6357 into four subnebulae: RCW 131a-d.
Bica et.al. report two infrared clusters [BDS2003] 100 and [BDS2003] 101 within RCW 131b = G353.1+0.7, which is the region of the nebula immediately surrounding Pismis 24. [3]
At the same distance as NGC 6334 and separated from it by a dark cloud.[2]
The RCW catalog divides NGC 6357 into four subnebulae: RCW 131a-d.
Bica et.al. report two infrared clusters [BDS2003] 100 and [BDS2003] 101 within RCW 131b = G353.1+0.7, which is the region of the nebula immediately surrounding Pismis 24. [3]
Notes
1. ^ Lortet, M. C., Testor, G., & Niemela, V. (1984). "Optical study of the galactic nebula NGC 6357 and of its stellar content, Pis 24 and the WC 6 star HD 157504", Astronomy and Astrophysics, Vol. 140, 24-32. [1984A&A...140...24L]
2. ^ Neckel, T. (1984). "Polarimetric and new photometric observations in the NGC6334/6357 region", Astronomy and Astrophysics, Vol. 137, 58-62. [1984A&A...137...58N]
3. ^ Bica, E., Dutra, C. M., Soares, J., et al. (2003). "New infrared star clusters in the Northern and Equatorial Milky Way with 2MASS", Astronomy and Astrophysics, Vol. 404, 223-232. [2003A&A...404..223B]
Distance estimates
1740 pc [1982ApJS...49..183B]1740 pc +/- 300 [1989BAICz..40...42A]
1900 pc +/- 400 [2012A&A...538A.142R]
1700 pc [2003A&A...404..223B]
Links
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Most of the sources used to create these nebula descriptions are listed in the
notes section for each description. In some cases,
for example the Avedisova, Humphreys and Reed catalogs, the source is used extensively and is not listed in the
individual nebula descriptions. See this catalog overview
for more information on the catalogs and the general sources used
to create these descriptions and this introduction to HII regions
on the general history of this area of astronomy.
This image was created using the POSS-II/UKSTU data of the Digitized Sky Survey and SuperCOSMOS using the process described here.
According to my correspondence with the Royal Observatory Edinburgh and the Space Telescope Science Institute, I am allowed to use the POSS-II/UKSTU data to create and display images for non-commercial purposes so long as I include this fine print for the SuperCOSMOS data:
Use of these images is courtesy of the UK Schmidt Telescope (copyright in which is owned by the Particle Physics and Astronomy Research Council of the UK and the Anglo-Australian Telescope Board) and the Southern Sky Survey as created by the SuperCOSMOS measuring machine and are reproduced here with permission from the Royal Observatory Edinburgh.
and this acknowledgement taken from the DSS site:
The Digitized Sky Surveys were produced at the Space Telescope Science Institute under U.S. Government grant NAG W-2166. The images of these surveys are based on photographic data obtained using the Oschin Schmidt Telescope on Palomar Mountain and the UK Schmidt Telescope. The plates were processed into the present compressed digital form with the permission of these institutions.
The Second Palomar Observatory Sky Survey (POSS-II) was made by the California Institute of Technology with funds from the National Science Foundation, the National Geographic Society, the Sloan Foundation, the Samuel Oschin Foundation, and the Eastman Kodak Corporation.
The UK Schmidt Telescope was operated by the Royal Observatory Edinburgh, with funding from the UK Science and Engineering Research Council (later the UK Particle Physics and Astronomy Research Council), until 1988 June, and thereafter by the Anglo-Australian Observatory. The blue plates of the southern Sky Atlas and its Equatorial Extension (together known as the SERC-J), as well as the Equatorial Red (ER), and the Second Epoch [red] Survey (SES) were all taken with the UK Schmidt.
The "Second Epoch Survey" of the southern sky was made by the Anglo-Australian Observatory (AAO) with the UK Schmidt Telescope. Plates from this survey have been digitized and compressed by the ST ScI. The digitized images are copyright ? 1993-5 by the Anglo-Australian Observatory Board, and are distributed herein by agreement.
The "Equatorial Red Atlas" of the southern sky was made with the UK Schmidt Telescope. Plates from this survey have been digitized and compressed by the ST ScI. The digitized images are copyright ? 1992-5, jointly by the UK SERC/PPARC (Particle Physics and Astronomy Research Council, formerly Science and Engineering Research Council) and the Anglo-Australian Telescope Board, and are distributed herein by agreement.
The compressed files of the "Palomar Observatory - Space Telescope Science Institute Digital Sky Survey" of the northern sky, based on scans of the Second Palomar Sky Survey are copyright ? 1993-1995 by the California Institute of Technology and are distributed herein by agreement. The compressed files of the "Palomar Observatory - Space Telescope Science Institute Digital Sky Survey" of the northern sky, based on scans of the Second Palomar Sky Survey are copyright ? 1993-1995 by the California Institute of Technology and are distributed herein by agreement.