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RA: 18h 03m 12s
Dec: −24° 23′ 0″
Ch: MSA:1392, U2:339, SA:22
Ref: SIMBAD, Archinal&Hynes (2003)
Type: open cluster, 22mn
Mag: B=?, V=?
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NGC 6523 is the star-forming core of M8 at the heart of the bright northwestern part of the nebula. NGC 6526 (which see) is the southeastern part of the nebula, and NGC 6530 is the bright star cluster 10-12 arcmin following N6523. NGC 6533 (which see) applies to the entire M8 complex, and IC 1271 and IC 4678 (both of which see) apply to condensations in its eastern reaches.
Also known as the Lagoon Nebula, it is plainly visible to the naked eye as a glowing patch just off the main stream of the Sagittarius Milky Way.
The open cluster associated with this nebula is NGC 6530.
Lacaille included it in his 1755 catalogue as Class III No. 13. In his half-an-inch 8x telescope he saw it as "three stars in nebulosity parallel to the Equator."
Messier observed it in 1764, describing at as "a cluster which looks like a nebula in an ordinary telescope of three feet but in a good instrument one observes only a large number of small stars... A fairly bright star nearby is surrounded with a very faint glow; this is 9 Sagittarii, 7 mag. The cluster appears elongated NE-SW. Diam 30'."
Sir William Herschel described it as "an extensive milky nebulosity divided into two parts; the north part being the strongest. Its extended exceeds 15'; the southern part is followed by a parcel of stars." In the Appendix to the 1912 'Scientific Papers of Sir William Herschel' this object is described as "1784, May 22. Large, extended, pretty bright, broad. The nebulosity of the milky kind, there are some pB stars in it, but they seem to have no connection with it, being of very different sizes and colours and resembling the other stars that are everywhere scattered about in this neighbourhood. This is probably the star surrounded with nebulosity mentioned by Messier. There is indeed one of the stars which are in the nebula that is somewhat larger than the rest and may be the only one he saw."
Sir John Herschel saw it as "a collection of nebulous folds and matter surrounding and including a number of dark, oval vacancies and in one place coming to so great a degree of brightness as to offer the appearance of an elongated nucleus. Superimposed on this nebula and extending in one direction beyond its area, is a fine and rich cluster of scattered stars which seems to have no connection with it as the nebula does not, as in the region of Orion, show any tendency to congregate about the stars.." At the Cape of Good Hope, he observed it with an 18-inch f/13 speculum telescope. He recorded it as "A noble nebula; to be monographed. The star taken is = 9 Sagittarii 7m. It is followed by a great cluster VI.13, of which with the nebula fills many fields." On a second occassion he called it "a superb nebula... See plate 1, fig 1."
Webb called it "a splendid galaxy object, visible to naked eye. In a large field we find a bright coarse triple star, followed by a resolvable luminous mass, including two stars, or starry centres, and then by a loose and bright cluster enclosed by several stars; a very fine combination..."
See: Barnard, E.E. (1908) Some notes on nebulae and nebulosities. Astr. Nachr., No.4239.
Barns, Charles Edward (1927) "1001 Celestial Wonders as observed with home-built instruments"
C E Barns wrote of it as "myriads of low-mag stars and a few brighter units resembling somewhat the Pleiades, involved in wide wastes of incandescent hydrogen and helium, overflung with dark absorbing patches.."
Burnham notes that the discovery of M8 is often credited to Le Gentil in 1747, who described it as "a small nebulosity like the tail of a comet with numerous stars... like the more transparent and whitish localities of the Milky Way." Burnham further writes that "it seems that it was recorded by Flamsteed as a "nebulosum" preceding the "Bow of Sagittarius" as early as 1680; de Cheseaux in 1746 also refers to a "cluster in Sagittarius' bow."
Burnham notes that the western half of M8 "is dominated by two bright stars just 3' apart; the southern star is 9 Sagittarii... Just 3' WSW from 9 Sagittarii lies the brightest segment of the nebulosity, a 'figure 8' shaped knot about 30" in size and often called from its shape "The Hourglass"..."
Galactic and Extragalactic Studies, III. Photographs of thirty southern nebulae and clusters. Proc. N.A.S., 26, 31-36.
Ced 152a (NGC 6523)
Position (1900): RA 17 57.6, Dec - 24 23
Star: Cl (Mp=5.4, , SpT=O5, B0)
Spectrum of nebula: emission spectrum (observed)
Classification: Nebulous cluster (Nebulous envelop of intricate structure, eg. NGC 2175)
Notes: "152 a = NGC 6523 = GC 4361 = h 3722 = M 8 = Lacadle III 13 = "The Lagoon nebula". Disc. Legentil 1748 (Compare Chapter I p 13). FA 62. WP 92. (30, 51, 57, 66, 74, 85, 88 Pl 42 Pl 44, Pl 49 Pl 51 Pl 52, 93 Pl 29 Pl 30, 103, 114, 174, 191, 194, 210, 213, 2115, 216, 234, 260, 365, 366, 409, 413, 417, 449, 453, 482, 486, 511, 520, 531, 543, 559, 587, 617, 630 Pl 4 Pl 6 Pl 7, 682, 715, 717, 747, 753, 767). R. The two stars -24 13814 = HD 164794 = CPD -24 6144 = Boss 24574, and -24 13816 = CPD -24 6146 = HD 164816 are involved together with the open cluster NGC 6530 = GC 4366 = h 3725. Other HD stars within the boundary of the nebula : -24 13780 = HD 164515. -24 13786 = HD 164535. -24 13783 = HD 164536. -24 13787 = HD 164537. -24 13793 = HD 164584. -24 13791 = HD 164585. -24 13795 = HD 164602. -24 13803 = HD 164705. -24 13812 = HD 164793. -24 13826 = HD 164865. -24 13832 = HD 164906. -24 13839 = HD 164933. -24 13845 = HD 164947. -24 13843 = HD 161448. -24 13864 = HD 165052. -24 13869 = HD 165133. -24 13880 = HD 165246. -24 13879 = HD 165247. The brightest part of the nebula has also been listed as -24 13806 = HD 164740."
Exploring the Southern Sky: A pictorial atlas from the European Southern Observatory. Springer-Verlag.
Scanned image on disk. [1987EtSS.........0L], plate 170.
Beverly Lynds (Astrophysical Journal Supplement, No 105, 1965) in her Catalogue of Bright Nebulae, notes that its maximum size is 45' x 30'.
Duncan, J. C. (1920) Bright nebulae and star clusters in Sagittarius and Scutum photographed with the 60-inch reflector. Astrophys. J., 51, 4-12.
The RNGC (Sulentic and Tifft 1973) notes that this is a 5.0 mag cluster associated with nebulosity.
Journal BAA, 35, Sep, p316
Given the name 'Lagoon Nebula' by Miss Clerke on account of its dark vacancies. Long exposure photos show the extent of cluster and nebulosity to be bout 45'x42'...
"!! nebula, irregular, similar to the Trifid Nebula, which it surpasses in size and brightness"
Bailey, S.I. (1908) A catalogue of bright stars and nebulae. Ann.Harv.Coll.Obs., 60(8), 199.
Remarks, p.218: "the spectrum is gaseous. this nebula is similar to the adjacent 'Trifid' nebula, which it surpasses in size and brightness, but the dark lanes which traverse it are less pronounced than those of the Trifid. it is closely associated with a fairly condensed cluster of stars, but the cluster and nebula are not concentric."
"A Catalogue of Estimated Parallaxes of 112 Nebulae, Open clusters and Star Groups", Vol 36 (4), p 107-115.
He gives the approx. diameter as 50x36 arcmin.
Harrington, P. (1990) An observer's guide to diffuse nebulae – II. Sky&Telescope, July, 97.
Hartung notes that "this fine nebula needs a large field and shows very extensive luminosity of varying brightness, involving two bright stars, with irregular lanes and followed by a bright open cluster... The whole field is wonderfully fine and varied, and small apertures show it well."
David Neilson (Oakland, California, USA), writes in the The Webb Society Nebulae and Clusters Section Report No. 10, July 1992: "Roughly bar-shaped, misty nebula surrounding four stars (mag 10-11). Due east, the dark rift is very distinct and is followed by a large, indistinct region of nebulosity (8-inch)."
John Bortle (Webb Society Quarterly Journal, January 1976) using 10x50 binoculars, estimates the visual magnitude of NGC 6523+6530 as 3.7.
Tom Lorenzin, in the e-version of "1000+ The Amateur Astronomers' Field Guide to Deep Sky Observing", notes: "5M; 80' x 40' extent! easily found with naked eye or binoculars; dark lane winds thru SW to NE; in E segment lies 1' diameter "HOURGLASS", 3' WSW of 9 SGR, illumination source; dark void surrounds 12M star just W of Hourglass's constriction; use high-x; cluster N6530 (10' diameter; 25-plus 7M and dimmer members) in N part of E segment; N-filter aids greatly; called "LAGOON"; one more of the best!."
"The Lagoon Nebula. With the possible exception of the Great Orion Nebula (M-42), this is probably the finest cluster and nebula combination in the heavens. A large and loosely scattered open cluster is seen in juxtaposition with a large and swirling mist of nebulosity. Many dark regions can be seen in looping patterns which are highlighted by the brighter regions. This object is easily seen in finder scopes, binoculars, and with the naked eye."
Observer: Lew Gramer; Your skills: Intermediate; Date and UT of Observation: 1997-07-4/5, 03:45 UT; Location: Savoy, MA, USA (42N, elev 700m); Site classification: rural; Limiting magnitude: 7.1 (zenith); Seeing: 5 of 10 - mediocre, near total cumulus; Moon up: no; Instrument: Naked eye, 50mm Simmons binoculars; Magnification: 1x, 7x; Filters used: None; Object: M8, M20, ngc6530 (globular ngc6544 not seen); Category: Reflection nebulae and open cluster; Constellation: Sgr; Data: mags 4.6, 6.3, 4.6 sizes 80'x40', 28', 15'; RA/DE: 18h00m -24o;
Description: Two bino fields (8o) due N of Sgr's teapot spout, and arrayed about the line formed by the mag 4-6 stars 4, 7 and 9 Sgr and the blurry open cluster n6530. M8 and M20 fall easily in the same field, forming between them a beautiful complex of BRIGHT haze and intermingled field stars. The dark bar running through the center of M8 was readily apparent even at 7x, as was some mottling whenever averted, concentrated vision was used. M20 to the N appeared much fainter, and (more suprisingly) larger than M8, and often required averted vision to see. No detail could be discerned in the extended haze. Interestingly, back- ground stars in this field were so thick and poorly resolved that they seemed to form a "bridge" of nebulous light between and among the two brighter (M8) & fainter (M20) true nebulae. No note of globular ngc 6544, SE of M8, was made at the time.
Observer: Alan Shaffer (e-mail: firstname.lastname@example.org, web: http://www.geocities.com/CapeCanaveral/3693/); Instrument: 25-inch Dobsonian reflector Location: Mt. Pinos, California, US; Light pollution: none Transparency: excellent Seeing: excellent; Time: Sat Jun 7 10:00:00 1997 UT Obs. no.: 142;
Beautiful object under incredable skies. I have not seen such clear skies in 15 years. The O-III filter made the Lagoon Nebula jump out in the 10" as well as the 25" scopes. Very bright and large. I could actually abserve it with the naked eye, no problem. Very beautiful and large. The first object of many, many hours of observing to come.
Observer: John Callender (e-mail: email@example.com, web: http://www.west.net/~jbc/); Instrument: 8-inch Dobsonian reflector Location: Carpinteria, CA, USA; Light pollution: light Transparency: good Seeing: fair; Time: Sun Jun 29 10:15:00 1997 UT Obs. no.: 171;
With the summer Milky Way arcing high over my head and Sagittarius on the meridian, I couldn't resist a quick sweep at 49x before coming in from my late-night (for me) observing session. The Lagoon Nebula was swept up easily, and was beautiful, of course (along with its associated cluster, NGC 6530).
Steve Coe, observing with a 13" f/5.6, notes: "(M 8) Very bright, very, very large, somewhat compressed cluster with lots of nebulosity. With the 2" eyepiece that gives a one degree field with the 13", the entire field is nebulous and the dark lane that gives the Lagoon its' name is obvious. I counted 40 stars included within the cluster and there are another 50 stars among the outer parts of the nebula and 10 of the stars are within the dark lane. Going to 100X shows the west side of the nebulosity is brightest and adding the UHC makes the nebula grow 1.5 times in size. I don't like the view with the UHC filter because it dims the stars involved and that is a large part of the beauty of this area of the sky. The Lagoon is an obvious naked eye spot in the Milky Way, even on a mediocre evening. In the finder or 10X50 binoculars this area in spectacular, the Lagoon and Trifid fit in the same field with star chains and dark lanes winding their way through the entire field of view. This part of Sagittarius will be a favorite as long as people construct telescopes."
Date and Time: 25 October 2008, 20:15
Location: Prince Albert (Western Cape, South Africa).
Instrument: Orion XT10 10" f/4.7 Dobsonian Reflector
Eyepieces: 10mm (120x, 26′ FOV), 25mm (48x, 1° FOV)
Sky Conditions: Clear. Seeing: 7/10. Transparency: Good
96x (25mm barlowed): Reasonably bright nebula separated by dark band into two regions. Dark central band visible from East to West. Bright patch of nebulosity to SW, close to two bright stars. Open cluster to the SE with approx 26 stars visible.
Nebulosity fades towards edges and brightness varies throughout the nebula. Visible area of the nebula is about 30′. Reasonably easy to see after eyes are fully dark adapted. Edges are diffuse.
In a 15.5-inch working at 220X, the southern portion of nebulosity is not nearly as prominent as photographs show. The northern, dominating lobe of nebulosity has a highlight of brighter nebulosity on its northern edge. Contrary to its photographic appearance, the dark central "channel" seems to taper to a point near the open cluster. In small telescopes it is seen to consist of a fine irregular nebulosity enveloping a scattered open cluster [NGC 6530].
1997 April 21. Jonkershoek. 11x80 tripod-mounted. No moon. Bright, large complex region of cluster, dark neb and bright neb. Dark nebula forms a prominent division.
Location: Jonkershoek Nature Reserve, Assegaaibosch Station
Date: 1998 July 31 / August 01, 01:00-02:40 SAST
11x80 tripod-mounted binoculars (9.5 mag stars at times not easy)
Sky conditions: Mediocre (transp. low, seeing average, dew) The skies are showing the effects of the combination of pollution (mainly from a nearby wood-processing plant) and a stable inversion layer, turning daytime skies grey-blue, and night skies ashen.
Large (30' x 20', EW:NS) elongated nebulous patch with stars. Just to the west, detached from the grouping, lie two brightish stars (brightest is 7 Sgr). The nebulous body is divided into two sections, a westerly and an easterly component.
The western part contains 9 Sgr and a fainter companion, situated off-centre, and towards the east, within an irregularly round nebulous haze. Averted vision on 9 Sgr shows it has a distinct bright extension trailing away to the southwest.
The eastern haze, of a similar size, has a compact stellar knot as its brightest feature. This knot is set in an irregularly round nebulous envelope, which is richly sprinkled with small stars.
[Although the U339 chart shows the nebulosity extending to include 7 Sgr, this is not the case visually.]
Observing site: Pinnacles overlook
[18h 3m 48s, -24° 23' 0"] One of the glories of Sagittarius, a constellation that harbors may of them. Bright nebulosity illuminated by glittering stars. Always a beautiful, moving sight. Visible to the naked eye.
Observing site: Little Tycho Observatory
[18h 3m 48s, -24° 23' 0"] mv: , C1: mv:, C2: mv:. The wonderful nebulosity of M8 was not seen through the haze. Just the cluster itself.
Telescope: 8" Dobsonian – f5. Eyepiece 25mm. FOV- 60’
Sky conditions: Seeing 4/5
Apparent size: 60'x 60'
Actual dimensions: 90'x 90 (Cartes Du Ciel)
Emission Nebula in Sagittarius
A huge bright nebula, with a dark lane from N-S which branches towards the NW dividing the nebula into an elongated fuzzy cloud E and two clouds W of the lane.
The SW cloud appears brightest with two bright stars and a triangle of faint stars visible. There is a dark patch visible in the center of this cloud.
The NW cloud is quite faint with three stars in a row, middle star brightest
A pretty cluster of stars to the E
To the W and detached from the three main clouds there is a faint patch of nebulosity. The brightest star in fov lies in this region.
I see the Lagoon yes but it also looks like Mick Jagger’s lips if I turn it slightly anti-clockwise!
The Messier objects
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