Coalsack Nebula - Misplaced Pages

(Redirected from Coalsack) Dark nebula in the constellation Crux

Coalsack Nebula
Dark nebula
The Coalsack Nebula taken by the Wide Field Imager on the MPG/ESO 2.2-metre telescope
Observation data: J2000.0 epoch
Right ascension	12 50
Declination	−62° 30′
Distance	180 pc
Apparent magnitude (V)	–
Apparent dimensions (V)	7° × 5°
Constellation	Crux
Physical characteristics
Radius	30–35 ly
Absolute magnitude (V)	–

Notable features	–
Designations	Caldwell 99
See also: Lists of nebulae

The Coalsack Nebula (Southern Coalsack, or simply the Coalsack) is a dark nebula, which is visible to the naked eye as a dark patch obscuring part of the Milky Way east of Acrux (Alpha Crucis) in the constellation of Crux.

General information

Historically any other dark cloud in the night sky was called coalsack. The Coalsack Nebula was juxtaposed in 1899 by Richard Hinckley Allen through naming the Northern Coalsack Nebula.

The Coalsack Nebula covers nearly 7° by 5° and extends into the neighboring constellations Centaurus and Musca. The 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.

A depiction of the *emu in the sky* known as weitj. The weitj in the sky is male, and you can see them guarding their eggs. During Makuru (the coldest and wettest time of the year, that falls across June and July), which is an Australian Aboriginal constellation consisting of dark clouds rather than of stars. The European constellation on the right is Crux, or the Southern Cross, and on the left is Scorpius. The head of the emu is the Coalsack.

In Australian Aboriginal astronomy, the Coalsack 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 do not 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. There is also a reference by Gaiarbau (1880) regarding the coalsacks replicating bora rings on Earth. These astronomical sites allowed the spirits to continue ceremony similar to their human counterparts on Earth. As bora grounds are generally located on the compass points north–south, the southern coal sack indicates the ceremonial ring.

In Inca astronomy this nebula was called Yutu, after a partridge-like South American bird, or Tinamou.

In Popular Culture

The Coalsack Nebula and the galactic area surrounding it played a large role in Jerry Pournelle's CoDominium Universe, particularly The Mote in God's Eye and the sequel The Gripping Hand, both co-authored with Larry Niven. In these novels, a human-colonized system, New Caledonia, is on the opposite side of the Coalsack from Earth. Set against the Coalsack is a red supergiant, and between the supergiant and New Caledonia is a yellow F6 star, known as "The Mote in God's Eye".

References

"A Cosmic Sackful of Black Coal". Retrieved 15 October 2015.
^ Franco, G.P.A. (2000). "Interstellar Na I D lines towards the Southern Coalsack". Monthly Notices of the Royal Astronomical Society. 315 (3): 611–621. Bibcode:2000MNRAS.315..611F. doi:10.1046/j.1365-8711.2000.03434.x.
"Coalsack Nebula". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-09-30.
O'Meara, Stephen James (2012-04-23). "Where is the Northern Coalsack?". Astronomy.com. Retrieved 2023-02-10.
Darling, David J. (2004). The universal book of astronomy: from the Andromeda Galaxy to the zone of avoidance. Hoboken, New Jersey: Wiley. p. 351. ISBN 0471265691.
^ "The Coalsack and the Southern Cross". ESO. 3 December 2009. Retrieved 1 October 2018.
Songs of the Songmen, 28–30.
James B. Kaler (2002). The Hundred Greatest Stars. New York: Springer Science & Business Media. p. 5. ISBN 978-0-387-95436-3.
A. F. Aveni, ed. (2010). Archaeoastronomy in the New World : American primitive astronomy : proceedings of an international conference held at Oxford University, September, 1981. Cambridge: Cambridge University Press. ISBN 978-0521125475.

External links

v t e Caldwell catalogue
List	C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C16 C17 C18 C19 C20 C21 C22 C23 C24 C25 C26 C27 C28 C29 C30 C31 C32 C33 C34 C35 C36 C37 C38 C39 C40 C41 C42 C43 C44 C45 C46 C47 C48 C49 C50 C51 C52 C53 C54 C55 C56 C57 C58 C59 C60 C61 C62 C63 C64 C65 C66 C67 C68 C69 C70 C71 C72 C73 C74 C75 C76 C77 C78 C79 C80 C81 C82 C83 C84 C85 C86 C87 C88 C89 C90 C91 C92 C93 C94 C95 C96 C97 C98 C99 C100 C101 C102 C103 C104 C105 C106 C107 C108 C109
See also	Messier Catalogue Catalogue of Nebulae and Clusters of Stars New General Catalogue Index Catalogue Revised New General Catalogue Herschel 400 Catalogue
Category Commons Portal

Constellation of Crux

Stars

Bayer	α (Acrux) β (Mimosa) γ (Gacrux) δ (Imai) ε (Ginan) ζ η θ θ ι λ μ μ
Variable	R S T V W X BG BH BL BP BU BZ CD CH DL DS DU
HR	4729 4848 4887 4890
HD	106906 108147 (Tupã)
Other	NGC 4349-127 PSR B1259−63/LS 2883 WR 46

Exoplanets	HD 106906 b HD 108147 b

Star clusters	Dragonfish Nebula Jewel Box (κ) NGC 4103 NGC 4349 NGC 4609

Nebulae	Coalsack Nebula Dragonfish Nebula IRAS 12063-6259