The Sharpless Catalog

Click on the small images to see larger ones.

Navigate to nebula [ Previous | Next ]

Sh 2-81

Coordinates: (51.61°, -9.68°)
[ See details ]

Essentially nothing appears in the scientific literature on this nebula, which is located far below the galactic plane.

Sh 2-81 can be clearly seen in this WISE infrared image.

Sh 2-82

Coordinates: (53.54°, 0.01°)
[ See details ]

This combination HII region and reflection nebula, also called LBN 129 and DG 159, is ionised by the B0.5V star HD 231616. With the current distance estimate, it appears to be near the Vul OB4 association.

A more detailed image of this nebula can be found here and a wider scale image here. The person who created the second image calls this the Little Cocoon nebula - but I prefer to think of this pretty region as the Locket nebula as it looks like a heart-shaped locket to me.

Sh 2-83

Coordinates: (55.113°, 2.403°)
[ See details ]

This tiny HII region contains the infrared cluster [BDS2003] 13.

Sh 2-84

Coordinates: (55.84°, -3.79°)
[ See details ]

This HII region, also called LBN 131, is near in the sky to the Wolf-Rayet star WR 128. Both Sharpless and Avedisova list WR 128 as an ionising star. However, there is some controversy about whether Sh 2-84 is part of the ring nebula surrounding this star or lies at another distance.

A look at this region in hydrogen-alpha reveals that although WR 128 lies in this direction, Sh 2-84 appears to be the brightest part of an enormous ring of ionised gas that is not centred on WR 128 but may instead surround the O7.5 I supergiant QZ Sge. Given the size of the ring it may be much closer than the Wolf-Rayet star.

It also seems possible that both QZ Sge and WR 128 contribute to the nebulosity seen in this direction and so Sh 2-84 is not a single object.

Sh 2-85

Coordinates: (57.39°, 9.06°)
[ See details ]

This very faint nebula is ionised by the B3 V star HD 177347.

Sh 2-86

Coordinates: (59.37°, -0.16°)
[ See details ]

The HII region NGC 6820 contains the radio source W55 and is ionised by the star cluster NGC 6823, which is part of the Vul OB1 association.

You can view a more detailed visual image here. The true nature of the region is perhaps best understood by viewing this spectacular Spitzer infrared image.

Sh 2-87

Coordinates: (60.9°, -0.1°)
[ See details ]

This massive star formation region is associated with a 7000 solar mass molecular cloud and many sources in the far infrared.

You can see a good visual image of Sh 2-87 here and the Spitzer space telescope infrared view here.

Sh 2-88

Coordinates: (61.48°, 0.33°)
[ See details ]

This nebula associated with the Vul OB1 association consists of three regions - star formation began in a diffuse large nebula Sh 2-88A, then spread to the compact HII region Sh 2-88B1, ionised by an O8.5-9.5 V star, and then finally spread to the ultracompact Sh 2-88B2, ionised by a star dimmer than B0.5 V.

Avedisova lists three ionising stars: the O7 V star HD 338916, the O8.5 Ib supergiant HD 338926, and the B0.5 V star LS II +25 09.

You can see the Spitzer space telescope infrared view here.

Sh 2-89

Coordinates: (62.9°, 0.1°)
[ See details ]

According to a 1989 paper, Sh 2-89 is ionised by two uncatalogued O7 V and B1 V stars.

Sh 2-86, Sh 2-87, Sh 2-88 and Sh 2-89 are part of the HI supershell GSH 061+00+51. Sh 2-89 and Sh 2-90 lie at the north-east boundary of the dark nebula LDN 798.

You can see the Spitzer infrared image of this nebula here and a detailed IPHAS hydrogen-alpha image here.

Sh 2-90

Coordinates: (63.2°, 0.5°)
[ See details ]

Sh 2-90 is a blister on a 60 thousand solar mass molecular cloud and appears to be affected by gas streaming from the Vul OB1 association. It contains a cometary elephant trunk structure on its eastern edge which appears to have originated from a past disturbance from the southwest.

A more detailed visible light image of this nebula can be found here and the Spitzer infrared view here.

Navigate to nebula [ Previous | Next ]

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.