Messier 30

Discovered by Charles Messier on August 3, 1764.

Messier: M30.

August 3, 1764. 30. 21h 27m 05s (321d 46' 18") -24d 19' 04"
Nebula discovered below the tail of Capricorn, very near to the star 41 of that constellation, of 6th magnitude, according to Flamsteed. One sees it with difficulty with an ordinary telescope of 3.5-foot [FL]. It is round & contains no star; its position determined from Zeta Capricorni, M. Messier reported it on chart of the Comet of 1759. Mem. Acad. 1760, pl. II. (diam. 2')

[Note on the Chart, Mem. Acad. for 1760, p. 465, Plate 12, Planche II]
Nebula of 2 [arc] min diameter. discovered in 1764.

[Mem. Acad. for 1771, p. 446 (first Messier catalog)]
In the night of August 3 to 4, 1764, I have discovered a nebula below the great tail of Capricornus, & very near the star of sixth magnitude, the 41st of that constellation, according to Flamsteed: one sees that nebula with difficulty in an ordinary [non-achromatic] refractor of 3 feet [FL]; it is round, & I have not seen any star: having examined it with a good Gregorian telescope which magnifies 104 times, it could have a diameter of 2 minutes of arc. I have compared the center with the star Zeta Capricorni, & I have determined its position in right ascension as 321d 46' 18", & its declination as 24d 19' 4" south. This nebula is marked in the chart of the famous Comet of Halley which I observed at its return in 1759 (*).

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(*) See Mém. Acad. 1760, page 464
[p. 457] 1764.Aug. 3. RA: 321.46.18, Dec: 24.19. 4.A, Diam: 0. 2. Nebula without stars, near the star 41 which is below the tail of Capricornus, according to Flamsteed.

Bode: Bode 68.

A nebula.

William Herschel

[PT 1814, p. 270-271. Reprinted in: Scientific Papers, Vol. 2, p. 533WH 1818 p. 442, SP2 p. 598]
Connoiss. 30 is "A brilliant cluster, the stars of which are gradually more compressed in the middle. It is insulated, that is, none of the stars in the neighborhood are likely to be connected with it. Its diameter is from 2'40" to 3'30". The figure is irregularly round. The stars about the centre are so much compressed as to appear to run together. Towards the north, are two rows of bright stars 4 or 5 in a line."
In this accumulation of stars, we plainly see the exertion of a central clustering power, which may reside in a central mass, or, what is more probable, in the compound energy of the stars about the centre. The lines of bright stars, although by a drawing made at the time of observation, one of them seems to pass through the cluster, are probably not connected with it.

[PT 1818, p. 442. Reprinted in: Scientific Papers, Vol. 2, p. 598]
The 30th of the Connoissance. [M 30 = NGC 7099]
"1794, 7 feet finder. It is but just visible."
"1794, 7 feet telescope. It seems to be resolvable, but is too faint to bear a high power."
"1810, 10 feet telescope. With 71, it appears like a pretty large cometic nebula, very gradually much brighter in the middle. 1783, with 250 it is resolved into very small stars."
"1783, small 20 feet Newtonian, 12 inch diameter. Power 200; it consists of very small stars; with two rows of stars, 4 or 5 in a line."
"1783, large 20 feet Newtonian. Power 120; by a drawing of the cluster, the rows of stars probably do not belong to the cluster."
"1784, 1785, 1786, 20 feet telescope, power 157. A brilliant cluster."
"1810, large 10 feet telescope. With 171 and 220 the diametr is 3' 5"; it is not round."
By the observation of the 10 feet telescope, the profundity of this cluster is of the 344th order.

John Herschel (1833): h 2128.

h 2128 = M30.
Sweep 299 (September 23, 1830)
RA 21h 30m 41.5s, NPD 113d 55' 26" (1830.0) [Right Ascension and North Polar Distance]
Fine cluster; irreg R, with two projections A, B, at its northern side. (See fig. 90.) A is directed from the central brightness and consists of 3 or 4 bright stars 12 m; its position taken with microm = 350deg.4; B originates in the preceding side of the centre, and is directed in a position 331deg.7 in a line not passing the centre; diam = 6', stars = 12m; fine object; has a * 9 m preceding it (2 or 3 diameters by diagram).
Fine cluster; irregularly round, with two projections A, B, at its northern side. (See fig. 90.) A is directed from the central brightness and consists of 3 or 4 bright stars of 12th magnitude; its position [angle] taken with micrometer is 350.4 deg; B originates in the preceding side of the centre, and is directed in a position [angle] 331.7 deg in a line not passing the centre; diameter 6', stars of 12th magnitude; fine object; has a star of 9th magnitude preceding it (2 or 3 diameters by diagram).

Smyth: DCCXCI [791]. M30.

DCCXCI. 30 M. Capricorni.
AR 21h 31m 16s, Dec S 23d 52'.4
Mean Epoch of Observation: 1836.70 [Sep 1836]
[with drawing]
A fine pale white cluster, under the creature's caudal fin, and about 20 deg west-north-west of Fomalhaut, where it precedes 41 Capricorni, a star of 5th magnitude, within a degree. This object is bright, and from the straggling streams of stars on its borthern verge, has an elliptical aspect, with a central blaze; and there are but few other stars, or outliers, in the field.
When Messier discovered this, in 1764, he remarked that it was easily seen with a 3 1/2-foot [FL] telescope, that it was a nebula, unaccompanied by any star, and that its form was circular. But in 1783 it was attacked by WH [William Herschel] with both his 20-foot Newtonians, and forthwith resolved into a brilliant cluster, with two rows pf stars, four or five in a line, which probably belong to it; and thereforehe deemed it insulated. Independently of this opinion, it is situated in a blankish space, one of those chasmata which Lalande termed d'espaces vuides, wherein he could not perceive a star of the 9th magnitude in the achromatic telescope of sixty-seven millimétres aperture. By a modification of his very ingenious gauging process, Sir William considered the profundity of this cluster to be of the 344th order.
Here are materials for thinking! What an immensity of space is indicated! Can such an arrangement be intended, as a bungling spouter of the hour insists, for a mere appendage to the speck of a world on which we dwell, to soften the darkness of its petty midnight? This is impeaching the intelligence of Infinite Wisdom and Power, in adapting such grand means to so disproportionate an end. No imagination can fill up the picture of which the visual organs afford the dim outline; and he who confidently probes the Eternal Design cannot be many removes from lunacy. It was such a consideration that made the inspired writer claim, "How unsearchable are His operations, and His ways past finding out!"

John Herschel (1847): h 3878.

h 3878 = M. 30 = h. 2128
Sweep 474 (July 29, 1834)
RA 21h 30m 45.5s, NPD 113d 56' 38" (1830.0) [Right Ascension and North Polar Distance]
Glob. Cl.; B; l E; b M; 4' l, 3' br; all resolved into st 16 m, besides a few 12 m. Two lines of rather larger stars run out n f.
Globular Cluster; bright; little elongated; brighter toward the middle; 4' long, 3' broad; all resolved into stars of 16 m, besides a few of 12 m. Two lines of rather larger stars run out north following [NE].

John Herschel, General Catalogue: GC 4687.

GC 4687 = h 2128 = h 3878 = M30.
RA 21h 32m 26.0s, NPD 113d 47' 59.0" (1860.0) [Right Ascension and North Polar Distance]
!; Glob. Cl.; B; L; lE; gpmbM; st 12 ... 16. 3 observations by W. & J. Herschel.
Remarkable; globular cluster; bright; large; slightly extended [elongated] gradually pretty much brighter toward the middle; stars from 12th to 16th magnitude.
Remark: Figure in P.T. 33 [JH 1833], plate viii., fig. 90.

Dreyer (1877)

GC 4687, h. 2128, h. 3878 [M 30]. Drawing in Secchi, Plate IV, Fig. 9.

Dreyer: NGC 7099.

NGC 7099 = GC 4687 = h 2128 = h 3878; M 30.
RA 21h 32m 25s, NPD 113d 48.7' (1860.0) [Right Ascension and North Polar Distance]
!, Glob. Cl., B, L, lE, gpmbM, st 12...16; = M30
Remarkable, globular cluster, bright, large, slightly extended [oval], gradually pretty much brighter toward the middle [i.e., from its edge, it gradually brightens to a much more intense middle], stars from 12th to 16th magnitude.
Remark: Figures in P.T. 33 [JH 1833], plate viii., fig. 90, and Secchi [Secchi, Memorie dell' Osserv. del Collegio Romano, 1852-55], plate IV, fig. 9.

Curtis

[Descriptions of 762 Nebulae and Clusters photographed with the Crossley Reflector. Publ. Lick Obs., No. 13, Part I, p. 9-42]
NGC 7099, RA=21:34.7, Dec=-23:38. M. 30. Bright globular cluster 5' in diameter. 25 s.n.