The Sharpless Catalog

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Sh 2-131

Coordinates: (99.28°, 3.73°)
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Sh 2-131 surrounds the star cluster IC 1396 (also called Trumpler 37, including the O6 multiple HD 206267) and lies in the edge of the Cepheus bubble, the giant expanding shell of gas and dust surrounding the Cep OB2 association.

This image only shows a portion of this large nebula. You can see a much better image of Sh 2-131 here, and an image of a famous globule within Sh 2-131, the Elephant Trunk nebula (IC 1396a) here.

Sh 2-131 appears at the lower right of the much larger Cepheus bubble as seen in this infrared IRAS image.

Sh 2-132

Coordinates: (102.78°, -0.66°)
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This giant HII region, which I call the Dragon nebula, is ionised by two WR stars (WR 152 and WR 153) and OB stars in several embedded clusters. WR 153 and an O 8.5 star lie near the middle of the radio shell associated with this nebula.

Available distance estimates locate Sh 2-132 in the Cep OB1 association within the Perseus arm.

This nebula is also prominent in radio and infrared images.

Sh 2-133

Coordinates: (103.06°, 9.56°)
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Sh 2-133 is probably a part of a chain of ionized arcs surrounding the older group of the Cep OB2 association and is part of the Cepheus bubble.

Sh 2-134

Coordinates: (103.82°, 2.6°)
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This HII region is associated with an expanding bubble surrounding Cep OB2. Also associated with this bubble are the HII regions IC 1396 (also called Sh 2-131), Sh 2-129, Sh 2-133, and Sh 2-140.

Avedisova concludes that the 40 solar mass O6 Iab supergiant Lam Cep (HD 210839) is the exciting star for Sh 2-134. You can read about the controversy around the origin of this great Milky Way beacon star in the Cep OB2 section of the Clamshell (110° - 100°) sector portion of the Commentary on the Galactic Plane.

Sh 2-135

Coordinates: (104.57°, 1.34°)
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This nebula appears to be a blister on a dark dust cloud in front of the bright arc. The nebula is ionised by the O9.5V class BD+57 2513 and includes the star cluster Juchert 21.

Sh 2-136

Coordinates: (105.06°, 13.22°)
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This is a Bok globule, not an HII region. New stars are forming nside the glowing globule, [CB88] 230, within the Lynds dark nebula LDN 1177.

Another image of this object can be found here.

Sh 2-137

Coordinates: (105.63°, 7.85°)
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This HII region lies at a similar direction and distance as the Cepheus Bubble, a huge expanding shell of gas and dust surrounding the Cep OB2 association.

Avedisova identifies 5 ionising stars. The hottest of these is the O9.5 II multiple giant HD 207198.

Sh 2-138

Coordinates: (105.62°, 0.35°)
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Embedded in this compact HII region is a large star cluster resembling the Orion Trapezium cluster: it is centrally peaked around several massive stars, and is dense - more than 550 stars at its centre.

Sh 2-139

Coordinates: (105.8°, 0.09°)
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According to Avedisova, Sh 2-139 is ionised by two giant stars: LS III +57 38 (O9 III) and LS III +58 37 (B2 III). SIMBAD disagrees with the spectral classification of LS III +57 38, however, and gives it a much cooler spectral class of B5.

You can view an IPHAS hydrogen-alpha image of Sh 2-139 here.

Sh 2-140

Coordinates: (106.75°, 5.29°)
[ See details ]

Sh 2-140 is part of the Cepheus Bubble, the expanding shell of gas and dust surrounding the Cep OB2 association. The bright rim is created by the B0.5 V double star HD 211880 ionising a Bok globule located within the southwest side of the LDN 1204 molecular cloud.

Avedisova identifies three other potential ionising stars, including the O7 V star BD +62 2078. She places Sh 2-140 into the massive star formation region SFR 106.75+5.30, and lists 79 components, including 7 masers and the dark nebulae LDN 1204 and LDN 1206.

A good image of Sh 2-140 can be found here.

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Stewart Sharpless published the second and final version of his famous nebula catalog in 1959. Although astronomers publish articles referring to the Sharpless 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 Sharpless objects are clearly visible only in CCD images or in 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 northern hemisphere are in the Sharpless catalog so the 313 objects it contains are well worth examining carefully. (In fact there are more than 313 objects as subsequent research has shown that some of the Sharpless nebulae consist of more than one object.) Although the Sharpless catalog is only intended to be complete for objects visible north of declination -27 degrees, a similar catalog covering the southern hemisphere was published by Alex Rodgers, Colin Campbell, and John Whiteoak in 1960, which is largely an expansion of Colin Gum's earlier catalog. You can visit a gallery of these RCW nebulae here. At least 50 objects in the Sharpless catalog are also in the RCW catalog and I have noted this in the descriptions of these objects.

Most of the images used to illustrate the Sharpless catalog were created using the POSS-II/UKSTU data of the Digitized Sky Survey, or, where available, the more detailed SuperCOSMOS Sky Survey. In both cases, 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.