Coalsack Nebula
Encyclopedia
The Coalsack Dark Nebula (or simply the Coalsack) is the most prominent dark nebula
in the skies, easily visible to the naked eye
as a dark patch silhouetted against the southern Milky Way
. It was known pre-historically
in the Southern Hemisphere
and was observed by Vicente Yáñez Pinzón
in 1499. The Coalsack is located at a distance of approximately 600 light years away from Earth
, in the Crux constellation
.
by 5° and overlaps somewhat into the neighbour constellations Centaurus
and Musca
. Although this nebula was known to the people of the Southern Hemisphere in prehistoric times, its first observation was reported by Vicente Yáñez Pinzón in 1499.
It was named “il Canopo fosco” (the dark Canopus
) by Amerigo Vespucci and was also called “Macula Magellani” (Magellan's Spot) or “Black Magellanic Cloud” in opposition to the Magellanic Clouds
.
In 1970, Kalevi Mattila proved the Coalsack is not totally black; it has a very dim glow (10% of the brightness of the surrounding Milky Way) which comes from the reflection of the stars it obscures.
The Coalsack is not present in the New General Catalogue
and in fact does not have an identification number (outside of the Caldwell Catalogue
, in which it is C99).
The Coalsack is important in Australian Aboriginal astronomy
, and forms the head of the Emu
in the sky in several Aboriginal cultures. Amongst the Wardaman
people, it is said to be the head and shoulders of a law-man watching the people to ensure they don't break traditional law. According to a legend reported by W.E. Harney, this being is called Utdjungon and only adherence to the tribal law by surviving tribe members could prevent him from destroying the world with a fiery star.
In Inca astronomy, this nebula was called Yutu, meaning a partridge-like southern bird.
episodes "The Immunity Syndrome
", "Let That Be Your Last Battlefield" and "2001: A Space Odyssey" by Aurthur C.Clarke
The Coalsack figures prominently in the Larry Niven
and Jerry Pournelle
's science fiction
novel The Mote in God's Eye
and its sequels, The Gripping Hand
and Outies.
Dark nebula
A dark nebula is a type of interstellar cloud that is so dense that it obscures the light from the background emission or reflection nebula or that it blocks out background stars . The extinction of the light is caused by interstellar dust grains located in the coldest, densest parts of larger...
in the skies, easily visible to the naked eye
Naked eye
The naked eye is a figure of speech referring to human visual perception unaided by a magnifying or light-collecting optical device, such as a telescope or microscope. Vision corrected to normal acuity using corrective lenses is considered "naked"...
as a dark patch silhouetted against the southern Milky Way
Milky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
. It was known pre-historically
Prehistory
Prehistory is the span of time before recorded history. Prehistory can refer to the period of human existence before the availability of those written records with which recorded history begins. More broadly, it refers to all the time preceding human existence and the invention of writing...
in the Southern Hemisphere
Southern Hemisphere
The Southern Hemisphere is the part of Earth that lies south of the equator. The word hemisphere literally means 'half ball' or "half sphere"...
and was observed by Vicente Yáñez Pinzón
Vicente Yáñez Pinzón
Vicente Yáñez Pinzón was a Spanish navigator, explorer, and conquistador, the youngest of the Pinzón brothers...
in 1499. The Coalsack is located at a distance of approximately 600 light years away from Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
, in the Crux constellation
Crux
Crux is the smallest of the 88 modern constellations, but is one of the most distinctive. Its name is Latin for cross, and it is dominated by a cross-shaped asterism that is commonly known as the Southern Cross.-Visibility:...
.
General information
The Coalsack Dark Nebula covers nearly 7°Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
by 5° and overlaps somewhat into the neighbour constellations Centaurus
Centaurus
Centaurus is a bright constellation in the southern sky. One of the largest constellations, Centaurus was included among the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations.-Stars:...
and Musca
Musca
Musca is one of the minor southern constellations. The constellation was one of twelve constellations created by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman and it first appeared on a 35-cm diameter celestial globe published in 1597 in Amsterdam by...
. Although this nebula was known to the people of the Southern Hemisphere in prehistoric times, its first observation was reported by Vicente Yáñez Pinzón in 1499.
It was named “il Canopo fosco” (the dark Canopus
Canopus
Canopus |Alpha]] Carinae) is the brightest star in the southern constellation of Carina and Argo Navis, and the second brightest star in the night-time sky, after Sirius. Canopus's visual magnitude is −0.72, and it has an absolute magnitude of −5.53.Canopus is a supergiant of spectral...
) by Amerigo Vespucci and was also called “Macula Magellani” (Magellan's Spot) or “Black Magellanic Cloud” in opposition to the Magellanic Clouds
Magellanic Clouds
The two Magellanic Clouds are irregular dwarf galaxies visible in the southern hemisphere, which are members of our Local Group and are orbiting our Milky Way galaxy...
.
In 1970, Kalevi Mattila proved the Coalsack is not totally black; it has a very dim glow (10% of the brightness of the surrounding Milky Way) which comes from the reflection of the stars it obscures.
The Coalsack is not present in the New General Catalogue
New General Catalogue
The New General Catalogue of Nebulae and Clusters of Stars is a well-known catalogue of deep sky objects in astronomy. It contains 7,840 objects, known as the NGC objects...
and in fact does not have an identification number (outside of the Caldwell Catalogue
Caldwell catalogue
The Caldwell Catalogue is an astronomical catalog of 109 bright star clusters, nebulae, and galaxies for observation by amateur astronomers. The list was compiled by Sir Patrick Caldwell-Moore, better known as Patrick Moore, as a complement to the Messier Catalogue.The Messier Catalogue is used...
, in which it is C99).
Australian Aboriginal astronomy
Australian Aboriginal astronomy is a name given to indigenous Australian culture relating to astronomical subjects — such as the Sun and Moon, the stars, planets, and the Milky Way, and their motions on the sky...
, and forms the head of the Emu
Emu
The Emu Dromaius novaehollandiae) is the largest bird native to Australia and the only extant member of the genus Dromaius. It is the second-largest extant bird in the world by height, after its ratite relative, the ostrich. There are three subspecies of Emus in Australia...
in the sky in several Aboriginal cultures. Amongst the Wardaman
Wardaman
The Wardaman people are a small group of Indigenous Australians living about 200km South-West of Katherine in the Northern Territory of Australia...
people, it is said to be the head and shoulders of a law-man watching the people to ensure they don't break traditional law. According to a legend reported by W.E. Harney, this being is called Utdjungon and only adherence to the tribal law by surviving tribe members could prevent him from destroying the world with a fiery star.
In Inca astronomy, this nebula was called Yutu, meaning a partridge-like southern bird.
In fiction
The Coalsack is mentioned in the Star Trek: The Original SeriesStar Trek: The Original Series
Star Trek is an American science fiction television series created by Gene Roddenberry, produced by Desilu Productions . Star Trek was telecast on NBC from September 8, 1966, through June 3, 1969...
episodes "The Immunity Syndrome
The Immunity Syndrome
The Immunity Syndrome may refer to:* "The Immunity Syndrome" , an episode of Space: 1999* "The Immunity Syndrome" , a second season episode of Star Trek: The Original Series first broadcast January 19, 1968...
", "Let That Be Your Last Battlefield" and "2001: A Space Odyssey" by Aurthur C.Clarke
The Coalsack figures prominently in the Larry Niven
Larry Niven
Laurence van Cott Niven / ˈlæri ˈnɪvən/ is an American science fiction author. His best-known work is Ringworld , which received Hugo, Locus, Ditmar, and Nebula awards. His work is primarily hard science fiction, using big science concepts and theoretical physics...
and Jerry Pournelle
Jerry Pournelle
Jerry Eugene Pournelle is an American science fiction writer, essayist and journalist who contributed for many years to the computer magazine Byte and has since 1998 been maintaining his own website/blog....
's science fiction
Science fiction
Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
novel The Mote in God's Eye
The Mote in God's Eye
The Mote in God's Eye is a science fiction novel by American writers Larry Niven and Jerry Pournelle, first published in 1974. The story is set in the distant future of Pournelle's CoDominium universe, and charts the first contact between humanity and an alien species. The title of the novel is a...
and its sequels, The Gripping Hand
The Gripping Hand
The Gripping Hand is a 1993 novel by Larry Niven and Jerry Pournelle. It is a sequel to their multi-award-nominated 1974 work The Mote in God's Eye. The Gripping Hand is, chronologically, the last novel of the CoDominium universe it is set in...
and Outies.