The Sharpless catalog is a list of 313

H II region An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundred ...

s (emission

nebula A nebula ('cloud' or 'fog' in Latin; pl. nebulae, nebulæ or nebulas) is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regio ...

e) 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 Stewart Sharpless (March 29, 1926 – January 19, 2013) was an American astronomer who carried out fundamental work on the structure of the Milky Way galaxy. As a graduate student at Yerkes Observatory he worked under William Morgan with fellow g ...

in 1959 with 312 objects. Sharpless also includes some

planetary nebula A planetary nebula (PN, plural PNe) is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives. The term "planetary nebula" is a misnomer because they are unrelated to ...

e and

supernova remnant A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar mat ...

s, in addition to H II regions. In 1953 Stewart Sharpless joined the staff of the

United States Naval Observatory Flagstaff Station The United States Naval Observatory Flagstaff Station (NOFS), is an astronomical observatory near Flagstaff, Arizona, US. It is the national dark-sky observing facility under the United States Naval Observatory (USNO). NOFS and USNO combine ...

, where he surveyed and cataloged

s of the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...

using the images from the

Palomar Sky Survey Palomar may refer to: Places * Any of several locations in San Diego County, California: ** Palomar Mountain ** Palomar Observatory, located on Palomar Mountain ** Palomar College in San Marcos, California ** Palomar Medical Center in Escondido, ...

. From this work Sharpless published his catalog of H II regions in two editions: the first in 1953, with 142 nebula; and the second and final edition in 1959, with 312 nebulae.Stewart Sharpless
A Catalogue of H II Regions
''Astrophysical Journal'' Supplement, vol. 4, p.257, 1959 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.Galaxy Map – The Gum, RCW, Sharpless and BFS catalogs
/ref> This can make them difficult to find, so a revised catalog called BFS (Blitz, Fich and Stark) was released with 65 new regions and about 20 removals. Most of the removed items were the aforementioned nebula or remnants. The 312 items in Sharpless sometimes overlap with the 110

Messier object The Messier objects are a set of 110 astronomical objects catalogued by the French astronomer Charles Messier in his ''Catalogue des Nébuleuses et des Amas d'Étoiles'' (''Catalogue of Nebulae and Star Clusters''). Because Messier was only int ...

s (M), 7,840 objects in the

New General Catalogue The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxies, star clusters and ...

(NGC), the

Caldwell catalogue The Caldwell catalogue is an astronomical catalogue of 109 star clusters, nebulae, and galaxies for observation by amateur astronomers. The list was compiled by Patrick Moore as a complement to the Messier catalogue. While the Messier catalog ...

(itself a "best of" from other catalogues, with 109 items), and the

RCW catalog The RCW Catalogue (from Rodgers, Campbell & Whiteoak) is an astronomical catalogue of Hα-emission regions in the southern Milky Way, described in . It contains 182 objects, including many of the earlier Gum catalogue (84 items) objects. The la ...

. 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''

References

External links

Original catalogIllustrated and annotated commentary
*

SIMBAD SIMBAD (the Set of Identifications, Measurements and Bibliography for Astronomical Data) is an astronomical database of objects beyond the Solar System. It is maintained by the Centre de données astronomiques de Strasbourg (CDS), France. SIMBA ...

br>Sh2 listingSh2 images
{{Portal bar, Astronomy, Stars, Spaceflight, Outer space, Solar System Astronomical catalogues of nebulae H II regions 1953 documents 1953 in science

Examples

See also

References

External links