Gum and RCW Catalogs of Southern H II Regions

All 182 RCW objects by type, constellation and distance

In catalog order, which runs along the southern Milky Way from Monoceros through Puppis, Vela, Carina and Centaurus to Sagittarius. Sort any column, or type a name or constellation; the type buttons above the map also filter the table. 47 have their own page elsewhere on Go Astronomy, many of them Sharpless objects; those link to that page. 2 RCW numbers have no position in the sources used here and are listed without a page.

Colin Gum's catalog has 86 entries; 35 are identified with modern positions here

Gum's 1955 survey was the first of the southern emission nebulae, and RCW extended it five years later; most Gum objects are also RCW objects, and link to the same page. The largest is Gum 12 Gum Nebula, the Gum Nebula, 36° across in Vela and Puppis: the remains of a supernova, or an H II region lit by the hot stars nearby, astronomers still debate which. 51 Gum numbers have no modern identification or position in the sources used here.

29 RCW objects have a common name

• RCW 1 Parrot Nebula, reflection nebula in Canis Major
• RCW 2 Seagull Nebula (Mon), reflection nebula in Monoceros
• RCW 5 Thor's Helmet, emission nebula (H II region) in Canis Major
• RCW 11 Dolphin Head Nebula, emission nebula (H II region) in Canis Major
• RCW 14 Charlie Brown's Christmas Tree, open cluster in Canis Major
• RCW 16 Skull & Crossbones Nebula, emission nebula (H II region) in Puppis
• RCW 37 Pencil Nebula, emission nebula (H II region) in Vela
• RCW 43 Flying Jaw Nebula, planetary nebula in Vela
• RCW 48 Banana Nebula, emission nebula (H II region) in Carina
• RCW 51 Gem Cluster, emission nebula (H II region) in Carina
• RCW 53 Carina Nebula, emission nebula (H II region) in Carina
• RCW 57 Statue of Liberty Nebula, emission nebula (H II region) in Carina
• RCW 62 Lambda Centauri Nebula, emission nebula (H II region) in Centaurus
• RCW 76 Spiral Planetary Nebula, planetary nebula in Musca
• RCW 77 Engraved Hourglass Nebula, planetary nebula in Musca
• RCW 98 Coffee Bean Nebula, emission nebula (H II region) in Norma
• RCW 100 Fine Ring Nebula, planetary nebula in Norma
• RCW 101 Ant Nebula, planetary nebula in Norma
• RCW 114 Dragon's Heart Nebula, supernova remnant in Ara
• RCW 120 Green Ring Nebula, emission nebula (H II region) in Scorpius
• RCW 123 Cheerio Nebula, planetary nebula in Scorpius
• RCW 124 Bug Nebula, planetary nebula in Scorpius
• RCW 127 Cat's Paw Nebula, emission nebula (H II region) in Scorpius
• RCW 131 War and Peace Nebula, emission nebula (H II region) in Scorpius
• RCW 146 Lagoon Nebula, emission nebula (H II region) in Sagittarius
• RCW 147 Trifid Nebula, emission nebula and cluster in Sagittarius
• RCW 160 Omega Nebula, emission nebula and cluster in Sagittarius
• RCW 165 Eagle Nebula, emission nebula and cluster in Serpens
• RCW 174, emission nebula (H II region) in Serpens

The Gum and RCW catalogs cover the southern Milky Way that the Sharpless catalog misses

Sharpless stopped at declination -27°, the limit of the Palomar Sky Survey. Gum and RCW photographed from Mount Stromlo in Australia, where the southern Milky Way passes overhead. The most RCW objects lie in Scorpius (25), Sagittarius (24), Vela (19), Centaurus (16), Puppis (15), Norma (15). 37 RCW objects in Monoceros, Puppis, Sagittarius and Scorpius are also in the Sharpless catalog. From the northern United States most of these nebulae never rise; from the southern states the Sagittarius and Scorpius objects are well placed in summer.

The nearest RCW object with a measured distance is RCW 37 Pencil Nebula, 940 light-years away

Each dot is one nebula, on a scale where each step is ten times farther. 47 of the 182 RCW objects have a distance here. The farthest is RCW 89, 17,000 light-years away.

Both catalogs were made at Mount Stromlo Observatory near Canberra

Colin Gum (1924-1960) photographed the southern Milky Way in the light of hydrogen-alpha for his PhD and published "A Survey of Southern H II Regions" in 1955. He became head of optical astronomy at the University of Sydney in 1959 and died in a skiing accident at Zermatt, Switzerland, in 1960. That year A. W. Rodgers, C. T. Campbell and J. B. Whiteoak published "A Catalogue of H-alpha Emission Regions in the Southern Milky Way" in the Monthly Notices of the Royal Astronomical Society, from deeper H-alpha photographs: 182 regions, numbered RCW 1 to RCW 182.