The dark nebulae Barnard 169, 170 and 171 are in the constellation of Cepheus seen against the background stars of the milky way. Dark nebulae are interstellar clouds that contain a very high concentration of dust. This allows them to scatter and absorb all incident optical light, making them completely opaque at visible wavelengths. They are most obvious when located in front of a bright emission nebula or a dense background of stars like in this example. The average temperature inside a dark nebula ranges from about 10 to 100 Kelvin, allowing hydrogen molecules to form and star formation to take place. Large dark nebulae can contain over a million solar masses.
B169, 170 & 171
Telescope: 16″ f3.75 Dream Scope
Camera: FLI ML16803
Mount: ASA DDM85
Exposure: 7.5 hours (44x300s L + 3x15x300s RGB)
Acquisition: May – June 2021
Location: Southern Alps, France