The Sharpless Catalog

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Sh 2-281

Coordinates: (209.03°, -19.48°)
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This is the Orion nebula, best known as Messier 42. It is located within the Orion A molecular cloud and is ionised by the Trapezium (Theta-1 Orionis) multiple star system, dominated by the O6 V class multiple Theta-1 Orionis C.

There are thousands of good images of the Orion nebula available on-line. Two of the most interesting are the Spitzer infrared view and this incredibly detailed Hubble view.

Sh 2-282

Coordinates: (210.07°, -2.31°)
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The ionising star of this HII region, the pulsating variable O9.5III giant HD 47432 (the bright star in the upper part of the image), is probably a member of the Mon OB2 association. The HII region contains a system of eight cometary globules.

Sh 2-283

Coordinates: (210.83°, -2.56°)
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Sh 2-283 includes the infrared cluster [BDS2003] 84 and according to Avedisova is ionised by an uncatalogued B0 V class star (MFJ Sh 2-283 8).

Russeil concludes the Sh 2-283 to Sh 2-286 are all part of one star formation region located in the Milky Way's Cygnus (Outer) arm. These nebulae are described in detail in the description of the Monoceros Arc (220° - 210°) sector in the Commentary on the Galactic Plane.

Sh 2-284

Coordinates: (212.0°, -1.31°)
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This large complex of HII regions is associated with the 6 million year old low metal star cluster Dolidze 25 and is one of the few relatively unobscured major star formation regions in the outer galaxy.

Russeil concludes the Sh 2-283 to Sh 2-286 are all part of one star formation region located in the Milky Way's Norma (Outer) arm. These nebulae are described in detail in the description of the Monoceros Arc (220° - 210°) sector in the Commentary on the Galactic Plane.

You can see an excellent hydrogen-alpha image of this nebula here and a combined infrared and hydrogen-alpha image here.

Sh 2-285

Coordinates: (213.81°, 0.62°)
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Sh 2-285 contains at least two B0 V stars (LS VI -0 9 and MFJ Sh 2-285 1) and the infrared cluster [BDS2003] 85.

Russeil concludes the Sh 2-283 to Sh 2-286 are all part of one star formation region located in the Milky Way's Cygnus (Outer) arm. These nebulae are described in detail in the description of the Monoceros Arc (220° - 210°) sector in the Commentary on the Galactic Plane.

Sh 2-286

Coordinates: (217.32°, -1.37°)
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Sh 2-286 contains the infrared cluster [BDS2003] 88 and appears in the direction of the molecular cloud [MAB97] 217.38-1.38.

Russeil concludes the Sh 2-283 to Sh 2-286 are all part of one star formation region located in the Milky Way's Cygnus (Outer) arm. These nebulae are described in detail in the description of the Monoceros Arc (220° - 210°) sector in the Commentary on the Galactic Plane.

Sh 2-287

Coordinates: (218.12°, -0.38°)
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Sh 2-287 appears to be associated with the massive cold Maddalena's cloud in the Perseus arm. It contains 4000-5000 solar masses of gas and dust and a bipolar nebula, NS 14 (BFS 57).

Avedisova concludes that Sh 2-287 is ionised by the O9.5 V star LS VI -04 19 and places it in star formation region 218.12-0.38 with 19 components, including the eight sources of the infrared complex FT 91 ([FT96] 218.1-0.4), several other infrared sources, and the Herbig-Haro object HH 227.

You can read more about Sh 2-287 and the larger region it is part of in the Sh 2-287 and the Maddalena cloud section of the description of the Monoceros Arc (220° - 210°) sector in the Commentary on the Galactic Plane.

Sh 2-288

Coordinates: (218.71°, 1.84°)
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This HII region, also called IC 466, is ionised by an O9V star.

You can see a slightly more detailed image here.

Sh 2-289

Coordinates: (218.84°, -4.55°)
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Avedisova concludes that Sh 2-289 is ionised by the B0.5 V class LSS 86 and an uncatalogued B1 V class star (MFJ Sh 2-289 2). Curiously, she omits two other ionising stars mentioned by MFJ: LS 85 and MFJ Sh 2-289 4. (Both are B-class according to SIMBAD.)

One huge distance estimate of more than ten thousand parsecs may place this nebula beyond even the Cygnus (Outer) arm. However, closer estimates are also available.

Sh 2-289 is located well below the galactic plane, and this may in part be related to an outer galaxy warp in the third quadrant which bends the galactic disk downwards.

See the Other Outer Arm Objects section
in the description of the Monoceros Arc (220° - 210°) sector in the Commentary on the Galactic Plane for more information and detailed references.

Sh 2-290

Coordinates: (219.1°, 31.3°)
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This is the planetary nebula Abell 31.

You can see a brighter image of this nebula 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.