Barnard 68
| Molecular cloud | |
|---|---|
| Bok globule | |
| dark nebula | |
Image of Barnard 68 in visible and near-infrared light | |
| Observation data: J2000.0 epoch | |
| Right ascension | 17h 22m 38.2s |
| Declination | −23° 49′ 34″ |
| Distance | 125 pc |
| Constellation | Ophiuchus |
| Physical characteristics | |
| Radius | 0.25 ly |
| Designations | Barnard 68, LDN 57 |
Barnard 68 is a molecular cloud, dark absorption nebula or Bok globule, towards the southern constellation Ophiuchus and well within the Milky Way galaxy at a distance of about 125 parsecs (407 light-years). It is both close and dense enough that stars behind it cannot be seen from Earth. American astronomer Edward Emerson Barnard added this nebula to his catalog of dark nebulae in 1919. His catalog was published in 1927, at which stage it included some 350 objects. Because of its opacity, its interior is extremely cold, its temperature being about 16 K (−257 °C/−431 °F). Its mass is about twice that of the Sun, and it measures about half a light-year across.