Lagoon Nebula

Lagoon Nebula
Emission nebula
H II region
M8, the Lagoon Nebula
Observation data: J2000 epoch
Right ascension18h 03m 37s[1]
Declination−24° 23′ 12″[1]
Distance4,100[2] ly   (1,250 pc)
Apparent magnitude (V)4.6[3]
Apparent dimensions (V)90 × 40 arcmins[3]
ConstellationSagittarius
Physical characteristics
Radius55 × 20 ly
DesignationsSharpless 25, RCW 146, Gum 72
M8 contains:
    NGC 6523, NGC 6530,[1]
    Hourglass nebula[4]
See also: Lists of nebulae

The Lagoon Nebula (catalogued as Messier 8 or M8, NGC 6523, Sharpless 25, RCW 146, and Gum 72) is a giant interstellar cloud in the constellation Sagittarius. It is classified as an emission nebula and has an H II region.

The Lagoon Nebula was discovered by Giovanni Hodierna before 1654[5] and is one of only two star-forming nebulae faintly visible to the eye from mid-northern latitudes. Seen with binoculars, it appears as a distinct cloud-like patch with a definite core. Within the nebula is the open cluster NGC 6530.[6]

  1. ^ a b c "M 8". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2006-11-15.
  2. ^ Arias, J. I.; Barbá, R. H.; Maíz Apellániz, J.; Morrell, N. I.; Rubio, M. (2006). "The infrared Hourglass cluster in M8". Monthly Notices of the Royal Astronomical Society. 366 (3): 739–757. arXiv:astro-ph/0506552. Bibcode:2006MNRAS.366..739A. doi:10.1111/j.1365-2966.2005.09829.x. S2CID 13907667.
  3. ^ a b Stoyan, Ronald (2008). Atlas of the Messier Objects: Highlights of the Deep Sky. Cambridge University Press. p. 88. ISBN 978-0-521-89554-5.
  4. ^ "SIMBAD Astronomical Database". Results for Hourglass Nebula. Retrieved 2006-12-22.
  5. ^ Kronberg, Guy McArthur, Hartmut Frommert, Christine. "Messier Object 8". messier.seds.org. Retrieved 11 April 2018.{{cite web}}: CS1 maint: multiple names: authors list (link)
  6. ^ N. F. H. Tothill; Marc Gagné; B. Stecklum; M. A. Kenworthy (2008). "The Lagoon Nebula and its Vicinity". In Bo Reipurth (ed.). Handbook of Star-Forming Regions: Volume 2 The Southern Sky. Astronomical Society of the Pacific. p. 53. ISBN 978-1-58381-671-4.