Bok globules
E476477
Bok globules are small, dense, and dark interstellar clouds of gas and dust that often serve as sites of early star formation.
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
astronomical object
ⓘ
dark nebula ⓘ interstellar cloud ⓘ |
| appearance | small dark patches against bright nebular backgrounds ⓘ |
| associatedWith | early stages of star formation ⓘ |
| blocks | background starlight ⓘ |
| canCollapseToForm |
binary star systems
ⓘ
low-mass stars ⓘ protostars ⓘ |
| classification | smallest type of dark molecular cloud ⓘ |
| composedOf |
dust
ⓘ
helium ⓘ molecular hydrogen ⓘ |
| contains |
complex organic molecules in some cases
ⓘ
gas ⓘ interstellar dust ⓘ molecules such as CO ⓘ |
| density | much higher than typical diffuse interstellar clouds ⓘ |
| discoveredBy | Bart Bok NERFINISHED ⓘ |
| discoveryDate | 1940s ⓘ |
| environment | often embedded in larger molecular cloud complexes ⓘ |
| evolvesInto | young stellar objects when collapse occurs ⓘ |
| exampleLocation |
Coalsack Nebula region
NERFINISHED
ⓘ
Horsehead Nebula region NERFINISHED ⓘ IC 2944 NERFINISHED ⓘ |
| feature | sharp edges against bright nebular backgrounds ⓘ |
| foundIn |
H II regions
ⓘ
star-forming regions ⓘ |
| location |
interstellar medium
ⓘ
molecular clouds ⓘ |
| namedAfter | Bart Bok NERFINISHED ⓘ |
| observationalChallenge | high extinction makes internal structure hard to observe in visible light ⓘ |
| observedIn |
infrared wavelengths for embedded protostars
ⓘ
optical wavelengths as dark silhouettes ⓘ radio wavelengths for molecular line emission ⓘ |
| property |
high density compared to surrounding interstellar medium
ⓘ
low temperature ⓘ |
| roleInAstrophysics |
laboratories for studying low-mass star formation
ⓘ
sites of isolated star formation ⓘ |
| shape |
irregular
ⓘ
roughly spherical ⓘ |
| stability | can be gravitationally bound ⓘ |
| studiedUsing |
infrared space telescopes
ⓘ
millimeter-wave telescopes ⓘ |
| surfaceBrightness | very low ⓘ |
| typicalMass | about 2 to 50 solar masses ⓘ |
| typicalSize | about 1 light year across or less ⓘ |
| typicalTemperature | about 10 Kelvin ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject surface form:
NGC 281