A dark nebula is an interstellar cloud of cosmic dust that’s so dense it absorbs, scatters and blocks visible light, making it appear inky black when viewed against the starry cosmos.
Famous examples of a dark nebula include the Coalsack Nebula, the Horsehead Nebula and the Snake Nebula.
Coalsack Dark Nebula by David Slack, Prudhoe, UK. Equipment: Modified Canon 1000d, Tamron 55-200mm lens, Hoya UV/IR block filter, iOptron Sky Tracker Mount
Many dark nebulae are known as Barnard objects and are catalogued using the ‘Barnard’ designation followed by a number, like Barnard 363 (below).
These are named after Edward Emerson Barnard, an American astronomer who published a record of dark nebulae known as the Barnard Catalogue in 1919, and an extended list posthumously in 1927.
Barnard 363 by Dan Crowson, Dardenne Prairie, Missouri, USA. Equipment: SBIG ST-8300M, Astro-Tech AT90DT
Dark nebulae are irregular in shape, unlike certain kinds of nebulae like planetary nebulae, which generally have a spherical appearance.
While dark nebulae may seem like foreboding, lifeless cosmic objects, in actual fact many of them are active regions where hydrogen molecules form and stars are born.
These stars are often hidden from optical light due to the density of the dark nebula in which they’re born, but radio and infrared telescopes allow astronomers to peer through the cosmic dust and get a closer look at the star formation occurring within.
The Snake Nebula (B72) by John Chumack, Dayton, Ohio, USA. Equipment: Baader Modified Canon Rebel Xsi, 5.5″ Newtonian Reflector John Chumak
A dark nebula may be the dense core of a Giant Molecular Cloud a million times more massive than the Sun, or they could take the form of compact molecular clouds known as Bok Globules, just 2,000 times the mass of the Sun.
Bok globules are a type of dark nebula named after the Dutch-American astronomer Bart Bok, and are thought to be the precursor to protostars, just waiting to gain enough mass that they collapse, igniting the process of star formation.
Bok Globules in the Rosette Nebula by Adam Leach, Kent, 25 February – 3 March 2019. Equipment: Atik 314L CCD camera, Altair Starwave 102ED refractor, Sky-Watcher HEQ5 Pro SynScan mount.
It is also worth pointing out that a dark nebula is not the same as dark matter. Dark matter is an invisible substance thought to make up about 27% of all matter in the Universe, and which is hypothesised because of its gravitational effect on directly observable objects like galaxies.
Below is a selection of images of dark nebulae captured by BBC Sky at Night Magazine readers and astrophotographers.
For advice on imaging the night sky, read our beginner’s guide to astrophotography or discover our pick of the best astrophotography cameras.
And don’t forget to send us your images or share them with us via Facebook, Twitter and Instagram.
LBN 777 – The Baby Eagle by Bob Franke, Chino Valley, AZ USA. Equipment: Takahashi FSQ-106ED, Losmandy G11 mount, SBIG STF-8300M, Baader LRGB filters.
Baby Eagle by Peter Martin, Ireland. Equipment: Orion Optics AG10, Starlight Express H694, Avalon Mount.
Barnard 323 & 324 by Dan Crowson, Dardenne Prairie, Missouri, USA. Equipment: SBIG ST-8300M, Astro-Tech AT90DT
Dark nebulae and gas clouds in Cygnus by André van der Hoeven, HI-Ambacht, The Netherlands. Equipment: TEC-140, QSI-583, Skywatcher NEQ-6
Dark Nebulae and Gas Clouds in Cygnus by André van der Hoeven, HI-Ambacht, The Netherlands. Equipment: TEC-140, QSI-583, Skywatcher NEQ-6
Barnard 6 (LDN 1387) by Dan Crowson, Dardenne Prairie, Missouri, USA. Equipment: SBIG ST-8300M, Astro-Tech AT90DT.
B142 & B143 Dark Nebulae by Mark Griffith, Swindon, Wiltshire, UK. Equipment: Skywatcher NEQ6 pro mount & Equinox 80mm refractor, Atik 383L+ camera, motorised filter wheel and Astronomik LRGB filters.
Barnard 143 (B143) by Zlatko Orbanic, Pula, Croatia. Equipment: Sky Watcher NEQ 6 Pro, Apo 130/900+F/R 0,80, Canon EOS 500D Modif.
LBN468 by Patrick Gilliland, Worcestershire, UK. Equipment: Paramount ME, Officina Stellare RH 200, FLI ML8300, Atlas Focuser, Astrodon Filters
Barnard 164 (LDN 1070) by Dan Crowson, Dardenne Prairie, Missouri, USA. Equipment: SBIG ST-8300M, Astro-Tech AT90DT
LDN 673 – Dark Nebula by Bob Franke, Chino Valley, AZ USA. Equipment: Takahashi FSQ-106ED, SBIG STF-8300, Baader LRGB filters, Losmandy Gll mount
LDN 889 Dark Nebula by Rob Little, Corbridge, UK. Equipment: Takahashi FSQ106, 1.6 barlow, ATIK 383L+, NeQ6Pro mount, Narrowband HA and OIII
vdB-27 & CED-30 by Bob Franke, Chino Valley, Arizona USA. Equipment: Takahashi FSQ-106ED, SBIG STF-8300M, Baader LRGB filters, Losmandy G11 mount
LDN 935 – Gulf of Mexico Nebula by José J. Chambó, Hoya Redonda, Valencia, Spain. Equipment: GSO 8″ f/3.8, Canon EOS-100D
LDN1235 Shark Nebula with VDB149 and VDB150 by Andrea Pistocchini, Germignaga, VA, Italy. Equipment: Tecnosky 80/480, 0,8x reducer, Canon 450D, Neq6-PRO, Skywatcher 70/500, qhy5II Mono guide
Antares Region by Rafael Compassi, Presidente Lucena, Brazil. Equipment: Nikkor 135mm F/2.8 em F/4
GAL 110-13 and vdB 158 by Bob Franke, Chino Valley, Arizona, USA. Equipment: Takahashi FSQ-106ED, SBIG STF-8300, Baader LRGB filters, Losmandy G11 mount.
Barnards in Aries by Kfir Simon, Namibia. Equipment: 16″ f3.75 Dream Astrograph, Apogee Alta U-16M camera.
B30 + B31 + B32 + B225 by Dan Crowson, Dardenne Prairie, Missouri, USA. Equipment: SBIG ST-8300M, Astro-Tech AT90D
LDn1235 – VDB150 by Roger Brooker, Seasalter, Kent, UK. Equipment: Ts65q, QSI583, Baader LRGB filters, Eq6 pro mount