The Sharpless catalog is a list of 313 H II regions (emission nebulae) intended to be comprehensive north of declination −27°. (It does include some nebulae south of that declination as well.) The first edition was published in 1953 with 142 objects (Sh1), and the second and final version was published by US astronomer Stewart Sharpless in 1959 with 312 objects. Sharpless also includes some planetary nebulae and supernova remnants, in addition to H II regions.
In 1953 Stewart Sharpless joined the staff of the United States Naval Observatory Flagstaff Station, where he surveyed and cataloged H II regions of the Milky Way using the images from the Palomar Sky Survey. From this work Sharpless published his catalog of H II regions in two editions: the first in 1953, with 142 nebula;[1] and the second and final edition in 1959, with 312 nebulae.[2] [3]
Sharpless coordinates are based on the star catalogs Bonner Durchmusterung (BD) and Cordoba Durchmusterung (CD), but the second release was adjusted to the 1900 epoch.
In the second release, some coordinates for southern hemisphere regions have an uncertainty over 1 minute of arc.[4] This can make them difficult to find, so a revised catalog called BFS (Blitz, Fich and Stark) was released[4] with 65 new regions and about 20 removals.[4] Most of the removed items were the aforementioned nebula or remnants.[4]
The 312 items in Sharpless sometimes overlap with the 110 Messier objects (M), 7,840 objects in the New General Catalogue (NGC), the Caldwell catalogue (itself a "best of" from other catalogues, with 109 items), and the RCW catalog. Contemporary catalogs were Gum and RCW, but they mainly covered the southern hemisphere.
Examples of second Sharpless (1958 version) catalog; click on image for image credit, most of which are either various amateur astronomers, the ESO, ESA, or NASA
| Sh2 No. | A common name | Images | Names and designations | |
|---|---|---|---|---|
| 6 | Sh2-6, NGC 6302, Bug Nebula,PK 349+01 1, Butterfly Nebula, RCW 124, Gum 60, Caldwell 69 | |||
| 8 | ESO 392-EN 009, Sharpless 8, RCW 127, Gum 64, NGC 6334 | |||
| 11 | Sh2-11, NGC 6357, RCW 131, Gum 66, War and Peace Nebula | |||
| 25 | Sh2 25, RCW 146, Gum 72, Messier 8 | |||
| 29 | Sharpless 29 | Sh2 29 | ||
| 30 | Trifid Nebula | Sh2 30, Messier 20, NGC 6514, RCW 147, Gum 76 | ||
| 45 | Omega Nebula, Messier 17, NGC 6618, Swan Nebula, Sharpless 45, RCW 160, Gum 81 | |||
| 49 | Sh2 49, Messier 16, NGC 6611, RCW 165, Gum 83 | |||
| 64 | Sh2 64, RCW 174 | |||
| 101 | Sharpless 101, Cygnus Star Cloud | |||
| 105 | Sh2 105, NGC 6888, Sharpless 105, Caldwell 27 | |||
| 106 | Sh2-106, Celestial Snow Angel | |||
| 117 | NGC 7000, Caldwell 20 | |||
| 125 | IC 5146, Caldwell 19 | |||
| 140 | Sh2-140 | Sh2-140 | ||
| 155 | Sh2-155, Caldwell 9 | |||
| 158 | Sh2-158, NGC 7538 | |||
| 162 | Sh2-162, NGC 7635, Bubble nebula | |||
| 171 | Sh2-171, NGC 7822 | |||
| 184 | NGC 281, IC 11 | |||
| 191 | Sh2-191, Maffei 1, PGC 9892 | |||
| 197 | Sh2-197, Maffei 2, UGCA 39,[5] PGC 10217, | |||
| 199 | Sh2-199, LBN 667, Soul Nebula, IC 1848 (cluster only) | |||
| 211, 212 | Tribble Nebulae | NGC 1624, Sh2-211, Sh2-212 | ||
| 220 | NGC 1499, Sharpless 220 | |||
| 229 | Flaming Star Nebula, Caldwell 31, IC 405, Sh2-229 | |||
| 237 | Sharpless 237 | |||
| 238 | NGC 1555, Hind's Nebula, Sharpless 238 | |||
| 244 | Messier 1, NGC 1952, | |||
| 248 | IC 443, Sh2-248, Jellyfish Nebula | |||
| 275 | Sh2-275, CTB 21 | |||
| 279 | NGC 1973, NGC 1975, NGC 1977 | |||
| 276 | Sh2-276, Barnard's Loop | |||
| 277 | Sh2-271, NGC 2024 | |||
| 281 | Messier 42, NGC 1976, LBN 974 | |||
| 297 | Ced 90, LBN 1039 | |||
| 298 | Thor's Helmet, Gum 4, Sharpless 298, NGC 2359 |