Snake Nebula (Barnard 72)
History
Edward. E. Barnard found on photographs he made that dark markings in the sky were not always caused by a void of stars but by a dark opaque nebulae. He published his catalogue of 182 such «Dark Markings in the Sky» in 1919 where these nebula were listed as numbers 68 through 77. For nebula 72 (Barnard 72, B 72) he noted: «This is a striking object. It is a thin, curved black marking, the exact form of the letter s or the figure 5, as the imagination or point of view may dictate. The southeast branch runs east for some distance passing close to the star C.D. -23°13370 (9.9 mag). Its average thickness is about 2' to 3'.» [239] The nebulae 255 and 261 were added later in his «Photographic Atlas of Selected Regions of the Milky Way», published in 1927. [609]
Sometimes the Snake Nebula is also called the «Smoke of the Pipe Nebula» (Barnard 59, 65–67, and 78).
Physical Properties
| Name | Type | RA (J2000.0) | Dec (J2000.0) | Rvel [km/s] | z | Size ['] | Identifiers |
|---|---|---|---|---|---|---|---|
| Barnard 68 | DNe | 17h 22m 38s | -23° 49' 34" | 3.51 | 0.000012 | Barnard 68; LDN 57; [CB88] 82 | |
| Barnard 69 | DNe | 17h 23m 00s | -23° 53' 00" | 3 × 1 | Barnard 69; LDN 55; [DB2002b] G1.46+6.96 | ||
| Barnard 70 | DNe | 17h 23m 36s | -23° 58' 00" | 3 × 1 | Barnard 70; LDN 54; [DB2002b] G1.45+6.81 | ||
| Barnard 71 | DNe | 17h 23m 29s | -24° 02' 30" | Barnard 71; LDN 53 | |||
| Barnard 72 | DNe | 17h 23m 39s | -23° 41' 42" | Barnard 72; LDN 66; NAME Snake DCld | |||
| Barnard 73 | DNe | 17h 24m 06s | -24° 17' 00" | 2 × 1.5 | Barnard 73; [DB2002b] G1.33+6.53 | ||
| Barnard 74 | DNe | 17h 25m 06s | -24° 12' 00" | Barnard 74 | |||
| Barnard 75 | DNe | 17h 25m 00s | -21° 53' 00" | 11 × 11 | Barnard 75; LDN 112; [DB2002b] G3.43+7.64 | ||
| Barnard 76 | DNe | 17h 25m 00s | -24° 24' 00" | Barnard 76 | |||
| Barnard 77 | DNe | 17h 27m 58s | -23° 59' 58" | Barnard 77; IRAS 17249-2357; IRAS 17249-2401; LDN 69 | |||
| Barnard 255 | DNe | 17h 20m 36s | -23° 23' 00" | 5 × 5 | Barnard 255; LDN 59; [DB2002b] G1.57+7.69 | ||
| Barnard 261 | DNe | 17h 25m 51s | -23° 00' 57" | Barnard 261; IRAS 17228-2258; LDN 85 |
Finder Chart
The Snake nebula can be found in the constellation Ophiuchus. On 13 June it is in opposition to the Sun and crosses the meridian at local midnight. It is best visible in the months from January to October.
