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[M 9]

Messier 9

Observations and Descriptions

Discovered on May 28, 1764 by Charles Messier.

Messier: M9.
May 28, 1764. 9. 17h 05m 22s (256d 20' 36") -18d 13' 26"
Nebula, without star, in the right leg of Ophiuchus; it is round & its light is faint. Observed again on March 22, 1781. (Diam. 3')

[Mem. Acad. for 1771, p. 439 (first Messier catalog)]
In the night of May 28 to 29, 1764, I have determined the position of a new nebula which is situated in the right leg of Ophiuchus, between the stars Eta and Rho of that constellation; that nebula doesn't contain any star; I have examined it with a Gregorian telescope which magnifies 104 times; it is round its light is faint, & its diameter is about 3 minutes of arc: its right ascension is 256d 20' 36", & its declination 18d 13' 26" south.
[p. 455] 1764.May.28. RA: 256.20.36, Dec: 18.13.26.A, Diam: 0. 3. Nebula without stars, in the right leg of Ophiuchus, between the stars Eta & Rho of that constellation.

Bode: Bode 36.
A nebula.

Caroline Herschel
May 5, 1783. Observed M9, M4, and M23.

William Herschel
[PT 1800, p. 73, reprinted in Scientific Papers, Vol. 2, p. 45]
May 3, 1783. I viewed the nebula between Eta and Rho Ophiuchi, discovered by Mr. Messier, in 1764 [M 9 = NGC 6333].
"With a 10-feet reflector, and a magnifying power of 250, I see several stars in it, and make no doubt a higher power, and more light, will resolve it all into stars. This seems to be a good nebula for the purpose of establishing the connection between nebulae and clusters of stars in general."
June 18, 1784. The same nebula viewed with a large Newtonian 20-feet reflector; penetrating power sqrt(43*(188^ 2-21^ 2))/2 = 61.18; and a magnifyingpower of 157. "A bery large and very bright cluster of excessively compressed stars. The stars are but just visible, and are of unequal magnitudes: the large stars are red; and the cluster is a miniature of that near Flamsteed's 42d Comae Berenices [M53]. RA 17h 6' 32"; P.D. 108d 18'."
Here, a penetrating power of 29, with a magnifying power of 250, would barely shew a few stars; when, in the other instrument, a power 61 of the first sort, and only 157 of the latter, shewed them completely well.

[PT 1814, p. 278, reprinted in Scientific Papers, Vol. 2, p. 538]
Connoiss. 9 [M 9 = NGC 6333] is "A cluster of very compressed and extremely small stars. It is a miniature of the 53d [M53]."

[PT 1818, p. 437-438, reprinted in Scientific Papers, Vol. 2, p. 596]
The 9th of the Connoissance.
"1783, 10 feet telescope, power 250. I see several stars in it; and have no doubt a higher power and more light will resolve it into stars."
"1784, 1786, 20 feet telescope. A cluster of extremely compressed stars; it is a miniature of the 53d [M 53]."
By the observations of the 10 feet the profundity is at least of the 344th order. It is in the preceding branch of the milky way.

John Herschel (1833): h 1979.
h 1979 = M9.
Sweep 269 (July 15, 1830)
RA 17h 9m 6s +/-, NPD 108d 20' +/- (1830.0) [Right Ascension and North Polar Distance]
R; vglbM; 3 or 4' diam; v faintly seen in strong twilight. RA from Catal. PD very roughly determined.
Round; very gradually little brighter toward the middle; 3 or 4' diameter; very faintly seen in strong twilight. RA from Catalog. PD very roughly determined.

Smyth: DCIX [609]. M9.
DCIX. 9 M. Ophiuchi.
AR 17h 09m 42s, Dec S 18d 20'.7
Mean Epoch of Observation: 1834.54 [Jul 1834]
A globular galaxy-cluster, on the Serpent-bearer's left leg, with a coarse telescopic double star in the np quadrant. This fine object is composed of a myriad of minute stars, clustering into a blaze in the centre, and wonderfully aggregated, with numerous outliers seen by glimpses. It was registered by Messier in 1764; and described by him as a nebula, "unaccompanied by any star." The mean apparent place was carefully differentiated from Eta Ophiuchi. Sir William Herschel resolved it with his 20-foot reflector, in 1784; and he estimated its profundity as, at least, of the 344th order. He thinks it a miniature of No. 53 Messier; and it is one of those which forms a capital object, for proving space-penetrating power of a telescope. It lies 3 deg to the south-east of Eta, and rather more than a quarter of the way from Antares to Altair.

John Herschel (1847): h 3677.
h 3677 = M. 9 = h. 1979.
Sweep 699 (May 18, 1836)
RA 17h 9m 12.4s, NPD 108d 20' 55" (1830.0) [Right Ascension and North Polar Distance]
Glob. Cl.; B; R; g m b M; 4' ; resolved into st 14 m.
Globular Cluster; bright; round; gradually much brighter toward the middle; 4' [diameter]; resolved into stars of 14th magnitude.

John Herschel, General Catalogue: GC 4287.
GC 4287 = h 1979 = h 3677 = M9.
RA 17h 10m 57.6s, NPD 108d 22' 59.8" (1860.0) [Right Ascension and North Polar Distance]
Glob. Cl.; B; L; R; eCM; rrr; st 14. 6 observations by W. & J. Herschel.
Globular cluster; bright; large; round; extremely compressed in the middle; well resolved; stars of 14th magnitude.

Dreyer: NGC 6333.
NGC 6333 = GC 4287 = h 1979 = h 3677; M 9.
RA 17h 11m 0s, NPD 108d 21.9' (1860.0) [Right Ascension and North Polar Distance]
Glob. Cl., B, L, R, eCM, rrr, st 14; = M9
Globular cluster, bright, large, round, extremely compressed in the middle, well resolved, stars of 14th magnitude.

[Descriptions of 762 Nebulae ans Clusters photographed with the Crossley Reflector. Publ. Lick Obs., No. 13, Part I, p. 9-42]
NGC 6333, RA=17:13.3, Dec=-18:25. Bright globular cluster 3' in diameter. 2 s.n.
  • Observing Reports for M9 (IAAC Netastrocatalog)

    Hartmut Frommert
    Christine Kronberg

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    Last Modification: February 5, 2005