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[M 16]

Messier 16

Observations and Descriptions

Cluster M16 (NGC 6611) discovered by Philippe Loys de Cheseaux in 1745-46.
Independently rediscovered, and nebula IC 4703 discovered, by Charles Messier on June 3, 1764.

Messier: M16.
June 3, 1764. 16. 18h 05m 00s (271d 15' 03") -13d 51' 44"
A cluster of small stars, enmeshed in a faint glow, near the tail of Serpens, at little distance to the parallel of Zeta of this constellation; with an inferior telescope this cluster appears like a nebula. (diam. 8')

[Mem. Acad. for 1771, p. 442 (first Messier catalog)]
In the same night of June 3 to 4, 1764, I have discovered a cluster of small stars, mixed with a faint light, near the tail of Serpens, at little distance from the parallel of the star Zeta of that constellation: this cluster may have 8 minutes of arc in extension: with a weak refractor, these stars appear in the form of a nebula; but when employing a good instrument one distinguishes these stars, & one remarkes in addition a nebulosity which contains three of these stars. I have determined the position of the middle of this cluster; its right ascension was 271d 15' 3", & its declination 13d 51' 44" south.
[p. 455] 1764.Jun.3. RA: 271.15. 3, Dec: 13.51.44.A, Diam: 0. 8. Cluster of small stars mixed with nebulosity, near the tail of Serpens, little distant from the parallel of the star Zeta of that constellation.

De Chéseaux: No. 4.
A star cluster between the constellations of Ophiuchus, Sagittarius, and Antinous [now Scutum], of which RA is 271d 3' 10" and southern declination is 13d 47' 20".

Bode: Bode 52.
Star cluster with nebula.

Caroline Herschel
July 30. 1783. Observed M16, M2, M25 and M55.

William Herschel
[Unpublished Observations of Messier's Nebulae and Clusters. Scientific Papers, Vol. 2, p. 652]
1783, July 30. Large stars with small ones among them; within a small compass I counted more than 50, and there must be at least 100 without taking in a number of straggling ones, everywhere dispersed in the neighborhood.

John Herschel (1833): h 2006.
h 2006 = M16.
Sweep 34 (July 31, 1826)
RA 18h 9m 15s+/-, NPD 103d 50' 34" (1830.0) [Right Ascension and North Polar Distance]
No description.

Smyth: DCXLIII [643]. M16
DCXLIII. 16 M. Clypei Sobieskii [now Serpentis].
AR 18h 09m 44s, Dec S 13d 50'.5
Mean epoch of the Observation: 1835.56 [July 1835].
A scattered but fine large stellar cluster, on the nombril of Sobieski's shield, in the Galaxy, discovered by Messier in 1764, and registered as a mass of small stars in the midst of a faint light. As the stars are disposed in numerous pairs among the evenescent points of more minute components, it forms a very pretty object in a telescope of tolerable capacity. Its mean apparent place was obtained by differentiation with the equatorial [*] instrument upon Mu Sagittarii, from which it lies north-half-east, at 7 deg distance; where it is on the line produced between Theta Ophiuchi and Delta Aquilae, which also reaches Altair.
[*] Though I have written equatorial as a difference between the instrument and its equatorial relations, I have only custom to plead in justification. Thus the rare tract which Ramsden printed in 1774, is intitulated, a Description of a new universal Equatoreal. A copy of it is preserved in the British Museum, in the Opuscula Philosophica. (486.)

John Herschel, General Catalogue: GC 4400.
GC 4400 = h 2006 = M16.
RA 18h 10m 57.0s, NPD 103d 50' 2.2" (1860.0) [Right Ascension and North Polar Distance]
Cl; at least 100 st L & S. 3 observations by W. & J. Herschel.
Cluster; at least 100 large [bright] & small [faint] stars.


Dreyer: NGC 6611.
NGC 6611 = GC 4400 = h 2006; M 16.
RA 18h 10m 57s, NPD 103d 50.0' (1860.0) [Right Ascension and North Polar Distance]
Cl, at least 100 st L & S; = M16
Cluster, at least 100 large [bright] & small [faint] stars.

IC 4703. Roberts.
RA 18h 11m .., NPD 103d 50' (1860.0)
RA 18h 13m .., NPD 103d 49' (1900.0)
B, eL, Cl M16 inv
Bright, extremely large, cluster M16 involved.
[NGC 2000.0 erroneously classifies IC 4703 as an Open Cluster but that is already M16]

  • Observing Reports for M16 (IAAC Netastrocatalog)

    Hartmut Frommert
    Christine Kronberg

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    Last Modification: January 2, 2005