Lagoon Nebula

{{Short description|Emission nebula in Sagittarius}}

{{Infobox nebula

| name=Lagoon Nebula

| image=VST images the Lagoon Nebula.jpg{{!}}300px

| caption= M8, the Lagoon Nebula

| type= H II region

| epoch = J2000

| ra = {{RA|18|03|37}}{{cite simbad

| title=M 8

| access-date=2006-11-15}}

| dec = {{DEC|−24|23|12}}

| dist_ly= 4,100{{cite journal

| author=Arias, J. I.

| author2=Barbá, R. H.

| author3=Maíz Apellániz, J.

| author4=Morrell, N. I. |author-link4=Nidia Morrell

| author5=Rubio, M.

| date=2006

| title=The infrared Hourglass cluster in M8

| journal=Monthly Notices of the Royal Astronomical Society

| volume=366 | issue=3 | pages=739–757

| bibcode=2006MNRAS.366..739A

| doi=10.1111/j.1365-2966.2005.09829.x

| doi-access=free

|arxiv = astro-ph/0506552 | s2cid=13907667

}}

| dist_pc =1,250

| appmag_v = 4.6{{Cite book |first=Ronald|last=Stoyan|title=Atlas of the Messier Objects: Highlights of the Deep Sky |page=88 |publisher=Cambridge University Press |year=2008 |isbn=978-0-521-89554-5 }}

| size_v = 90 × 40 arcmins

| constellation = Sagittarius

| radius_ly = 55 × 20

| absmag_v =

| notes =

| names = Sharpless 25, RCW 146, Gum 72
M8 contains:
    NGC 6523, NGC 6530,
    Hourglass nebula{{cite web

| title=SIMBAD Astronomical Database

| work=Results for Hourglass Nebula

| url=http://simbad.u-strasbg.fr/Simbad

| access-date=2006-12-22

}}

}}

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 in 1654{{cite web |last1=Vowler |first1=Faith |last2=Bolles |first2=Dana |title=Messier 8 |url=https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-8/ |website=NASA Science |access-date=17 March 2025 |archive-url=https://archive.today/20250317060239/https://science.nasa.gov/mission/hubble/science/explore-the-night-sky/hubble-messier-catalog/messier-8/ |archive-date=17 March 2025 |language=en |date=12 September 2024 |quote=M8 was discovered in 1654 |url-status=live}}{{cite web|url=http://www.messier.seds.org/m/m008.html|title=Messier Object 8|first=Guy McArthur, Hartmut Frommert, Christine|last=Kronberg|website=messier.seds.org|access-date=11 April 2018}} 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.{{cite book|title=Handbook of Star-Forming Regions: Volume 2 The Southern Sky|editor=Bo Reipurth|chapter=The Lagoon Nebula and its Vicinity|page=53|author1=N. F. H. Tothill|author2=Marc Gagné|author3=B. Stecklum|author4=M. A. Kenworthy|publisher=Astronomical Society of the Pacific|date=2008|isbn=978-1-58381-671-4}}