The RCW Catalog

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RCW 131

Coordinates: (353.19°, 0.84°)
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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.

RCW 131a

Coordinates: (353.27°, 1.07°)
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If we think of the massive star formation region RCW 131 as a skeletal hand, then RCW 131a is the large arc of the curved fingers surrounding what appears to be empty space.

RCW 131b

Coordinates: (353.20°, 0.82°)
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RCW 131b is the core of the massive RCW 131 star formation region, surrounding the star cluster Pismis 24.

RCW 131c

Coordinates: (353.12°, 0.44°)
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If we think of the massive star formation region RCW 131 as a skeletal hand, then RCW 131c is in the wrist region in the direction of the star cluster AH03 J1725-34.4. According to a 2011 study, this little known star cluster is distinct from the nearby Pismis 24 cluster and includes at least 4 OB stars including the massive [N78] 49 (O4 III) and [N78] 51 (O3.5 V).

RCW 131d

Coordinates: (353.54°, 0.53°)
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If we think of the massive star formation region RCW 131 as a skeletal hand, then RCW 131d is in the wrist region. A 2011 study identifies a O7.5 class star ([GKK 2011] 1) with a bow shock that appears to have been ejected from the AH03 J1725−34.4 star cluster within RCW 131c.

RCW 132

Coordinates: (355.4°, 0.2°)
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This diffuse nebula is ionised by the binary O-star (O7V + O7V) HD 159176 in the star cluster NGC 6383.

RCW 133

Coordinates: (355.9°, 1.5°)
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This nebula surrounds the O9.5V binary HD 158186, which lies in the direction of the small cluster Antalova 1.

RCW 134

Coordinates: (358.34°, -1.85°)
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This HII region is ionised by the O8 V star HD 161853 and is part of the Sh 2-15 to Sh 2-20 complex of HII regions located in the Sgr OB5 association in the Sagittarius arm. It is the location of the radio source W25.

RCW 135

Coordinates: (358.96°, -0.72°)
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This is the planetary nebula Hen 2-277.

RCW 136

Coordinates: (359.0°, -3.6°)
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This is the planetary nebula Haro 1-44.

RCW 137

Coordinates: (0.0°, -0.6°)
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Sh 2-16 is part of the Sh 2-15 to Sh 2-20 complex of HII regions located in the Sgr OB5 association in the Sagittarius arm. It appears to be ionised by the O9.5 V star LSS 4381.

RCW 138

Coordinates: (0.02°, 0.13°)
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Sh 2-17 is part of the Sh 2-15 to Sh 2-20 complex of HII regions located in the Sgr OB5 association in the Sagittarius arm.

There are no papers suggesting ionising stars for Sh 2-17 and there are no OB stars in this direction in the Reed OB star catalog either. However, the infrared cluster [DB2000] 58 appears to be embedded in the nebula and may contain the ionising stars.

RCW 139

Coordinates: (0.1°, -0.8°)
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This small nebula is part of the Sh 2-15 to Sh 2-20 complex of HII regions located in the Sgr OB5 association in the Sagittarius arm. It lies next to RCW 140 (Sh 2-19).

No ionising stars are cited in the scientific literature but the nebula is believed to contain the infrared cluster [DB2000] 1 which may perhaps contain ionising stars.

RCW 140

Coordinates: (0.11°, -0.56°)
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This nebula is part of the Sh 2-15 to Sh 2-20 complex of HII regions located in the Sgr OB5 association in the Sagittarius arm.

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Alex Rodgers, Colin Campbell, and John Whiteoak, working at Australia's Mount Stromlo observatory under the direction of Dutch-American astronomer Bart Bok, published their nebula catalog in 1960. The RCW catalog is largely an expansion of Colin Gum's 1955 catalog. Although astronomers publish articles referring to the RCW nebulae almost every month, there seems to be few places on the Internet that bring together information on these nebulae as a whole - unlike, for example, the Messier catalog. This is most likely because the Messier objects are visible to anyone with a pair of binoculars or a small telescope. Most of the RCW objects are clearly visible only in long exposure CCD images or photographic plates taken by large telescopes. Fortunately some of these plates have now been digitally scanned and made publicly available.

Many of the brightest and most beautiful Milky Way star formation regions visible from the southern hemisphere are in the RCW catalog so the 182 objects it contains are well worth examining carefully. (In fact there are more than 182 objects as subsequent research has shown that some of the RCW nebulae consist of more than one object.) At least 50 objects in the RCW catalog are also in the Sharpless catalog and I have noted this in the descriptions of these objects.

Most of the images used to illustrate the RCW catalog were created using the SuperCOSMOS Sky Survey, with red = hydrogen-alpha, blue = UKST Blue and green = UKST Infrared. Because green represents infrared, the images are not quite the same as would be seen at purely visual frequencies. Green in these images usually reveals warm dust or red giant stars.

These images were 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.