Sharpless catalog

The Sharpless catalog is a list of 313 HII 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 HII regions.^[1]

In 1953 Stewart Sharpless joined the staff of the United States Naval Observatory Flagstaff Station,^[2] 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.^[3] The second and final edition was published in 1959 with 312 nebulae.^[2]^[4]

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.^[1]

In the second release, some coordinates for southern hemisphere regions have an uncertainty over 1 minute of arc.^[1] This can make them difficult to find, so a revised catalog called BFS (Blitz, Fich and Stark) was released.^[1] BFS has 65 new regions and about 20 removals.^[1] Most of the removed items were taken out because they were the aforementioned nebula or remnants.^[1]

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 (that itself is 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

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

Sh 2- #	A common name	Names and designations
6	NGC 6302	Sh2-6, NGC 6302, Bug Nebula, PK 349+01 1, Butterfly Nebula, RCW 124, Gum 60, Caldwell 69
8	NGC 6334	ESO 392-EN 009, Sharpless 8, RCW 127, Gum 64, NGC 6334
11	NGC 6357	Sh2-11, NGC 6357, RCW 131, Gum 66, War and Peace Nebula
25	Lagoon Nebula	Sh2 25, RCW 146, Gum 72, Messier 8
30	Trifid Nebula	Sh2 30, M20, NGC 6514, RCW 147, Gum 76
45	Omega Nebula	Omega Nebula, M17, NGC 6618, Swan Nebula, Sharpless 45, RCW 160, Gum 81
49	Eagle Nebula	Sh2 49, Messier 16, NGC 6611, RCW 165, Gum 83
64	W 40	Sh2 64, RCW 174
101	Tulip Nebula	Sharpless 101
105	Crescent Nebula	Sh2 105, NGC 6888, Sharpless 105, Caldwell 27
106	Sh2-106	Sh2-106, Celestial Snow Angel
117	North America Nebula	NGC 7000, Caldwell 20
125	Cocoon Nebula	IC 5146, Caldwell 19
140	Sh2-140	Sh2-140
155	Cave Nebula	Sh2-155, Caldwell 9
162	NGC 7635	Sh2-162, NGC 7635, Bubble nebula
184	NGC 281	NGC 281, IC 11
191	Maffei 1	Sh2-191, Maffei 1, PGC 9892
197	Maffei 2	Sh2-197, Maffei 2, UGCA 39,^[5]PGC 10217,^[5]
199	Soul Nebula	Sh2-199, LBN 667, Soul Nebula, IC 1848 (cluster only)
220	California Nebula	NGC 1499, Sharpless 220
229	IC 405	Flaming Star Nebula, Caldwell 31, IC 405, Sh2-229
238	NGC 1555	NGC 1555, Hind's Nebula, Sharpless 238
244	Crab Nebula	Messier 1, NGC 1952,
248	IC 443	IC 443, Sh2-248, Jellyfish Nebula
271	Flame Nebula	Sh2-271, NGC 2024
275	Rosette Nebula	Sh2-275, CTB 21
276	Barnard's Loop	Sh2-276, Barnard's Loop
281	Orion Nebula	M42, NGC 1976, LBN 974
298	NGC 2359	Thor's Helmet, Gum 4, Sharpless 298, NGC 2359