Messier 10

Discovered on May 29, 1764 by Charles Messier.

Messier: M10.

May 29, 1764. 10. 16h 44m 48s (251d 12' 06") -3d 42' 18"
Nebula, without stars, in the belt of Ophiuchus; near the 30th star of that constellation, of sixth magnitude, according to Flamsteed [30 Oph]. This nebula is beautiful & round; one can only see it with difficulty in an ordinary telescope of 3-feet [FL]. M. Messier has reported on the 2nd chart of the track of the comet of 1769. Mem. Acad. for the year 1775, plate IX. Observed again on March 6, 1781. (Diam. 4')

[manuscript note in Messier's personal copy:]
Observed again in the morning of March 6, 1781. "Always very fine." Seen again in the morning of March 10, 1790. Night-glass of Rebour.

[Mem. Acad. for 1771, p. 439 (first Messier catalog)]
In the night of May 29 to 30, 1764, I have determined the position of a nebula which I have discovered in the girdle of Ophiuchus, near the 30th star of that constellation, of sixth magnitude. according to the catalog of Flamsteed. When having examined that nebula with a Gregorian telescope of 30 pouces which magnified 104 times, I have not seen any star there: it is round & beautiful, its diameter is about 4 minutes of arc; one sees it difficultly with an ordinary [non-achromatic] refractor of one foot [FL]. Near that nebula one perceives a small telescopic star. I have determined the right ascension of that nebula as 251d 12' 6", & its declination as 3d 42' 18" south. I marked that nebula in the chart of the apparent path of the Comet which I have observed last year [the comet of 1769].
[p. 455] 1764.May.29. RA: 251.12. 6, Dec: 3.42.18.A, Diam: 0. 4. Nebula without stars, in the girdle of Ophiuchus, near the star 30 of that constellation, according to Flamsteed.

Bode: Bode 33.

2 nebulae without stars close together [with M12]
On August 14 [1774], I discovered in Ophiuchus two new nebulae not far from each other. One of them is situated south of 14, 16, 19 and 21 Oph near the western arm, the other below this one and eastward, closely west of 30 Oph. These nebulae appear very pale, and because of this, I found not very reliably the separation to Lambda as 6deg 7', to the star 14 as 3deg 50', and to 21 as 3deg 32'. The other one is separated from the 21st star by 5deg 32', and by 1deg 4' from the 30th, as shown in the second figure.

Koehler: Koehler No. 4

[Nebula] In Serpentarius [Ophiuchus], longitude 10d 20' [Sgr] [250d 20']; latitude 17d 35' north.

Caroline Herschel

May 22, 1783. Observed M10, M5 (which she first took for a comet), M11, and M12.

William Herschel

[PT 1800, p. 74, reprinted in Scientific Papers, Vol. 2, p. 46 (footnote)]
[M14 resembles M10 if it [M10] would be 1.5 times as far as it is.] The object referred to is No. 10 of the Connoissance des Temps for 1783, called "Nébuleuse sans étoile." My description of it is, "A very beautiful, and extremely compressed, cluster of stars; the most compressed part about 3 or 4' in diameter. R.A. 16h 46' 2"; P.D. 93d 46'."

[PT 1818, p. 438, reprinted in Scientific Papers, Vol. 2, p. 596]
The 10th of the Connoissance. [M 10 = NGC 6254]
"1783, 7 feet telescope. With 227 I suspected it to consist of stars; with 460 I can see several of them, but they are too small to be counted."
"1784, 1791, 20 feet telescope. A beautiful cluster of extremely compressed stars; it resembles the 53d [M53]; and the most compressed part is about 3 or 4 minutes in diameter."
The profundity of this cluster, by the observation of the 7 feet telescope, is of the 243d order.

John Herschel (1833): h 1972.

h 1972 = M10.
Sweep 75 (July 2, 1827)
RA 16h 48m 10.8s, NPD 93d 50' +/- (1830.0) [Right Ascension and North Polar Distance]
A globular cluster of scattered stars, but twilight and moon interfere. (PD from another sweep, not having been taken.)

Sweep 146 (April 15, 1828)
RA 16h 48m 14.3s, NPD 93d 49' +/- (1830.0)
Is brighter than 12M [Messier 12] and rather larger and looser. (This disagrees with an obs of 12M [M12].) The bright part = 4', but the cl fills two third of the field = 10'. Stars 9 ... 15m.
Is brighter than M12 and rather larger and looser. (This disagrees with an obs of M12.) The bright part is 4' in diameter, but the cluster fills two third of the field, i.e. 10' diameter. Stars of 9th to 15th magnitude.

Sweep 5 (May 21, 1825)
L; roundish; g p m b M; 10' stars 15..20 m.
large; roundish; gradually pretty much brighter toward the middle; 10' diameter, stars of 15th to 20th magnitude.

Viewed June 1, 1831. A superb cluster of very compressed stars, g b M. The stars are 10 ... 15m, and run up to a blaze in the centre, but I see no nucleus. Diam about 6'; a noble object.
Viewed June 1, 1831. A superb cluster of very compressed stars, gradually brighter toward the middle. The stars are of 10th to 15th magnitude, and run up to a blaze in the centre, but I see no nucleus. Diameter about 6'; a noble object.

Smyth: DXCV [595]. M10.

DXCV. 10 M. Ophiuchi.
AR 16h 48m 45s, Dec S 3d 51'.8
Mean Epoch of Observation: 1835.54 [Jul 1835]
A rich globular cluster of compressed stars, on the Serpent-holder's right hip. This noble phenomenon is of a lucid white tint, somewhat attenuated at the margin, and clustering to a blaze in the centre. It is so easily resolvable with very moderate means, that we are surprised at Messier's remark, on registering it in 1764: "A beautiful round nebula. It may be seen, with attention, by a telescope of three feet in length." The mean apparent place of the central mass, was differentiated with Epsilon Ophiuchi, which it follows nearly on the same eastern parallel, at about 8deg distance; being nearly midway between Beta Librae and Alpha Aquilae, and about a degree preceding [west of] 30 Ophiuchi, a star of the 6th magnitude, with a smaller one preceding it. Sir William Herschel resolved this object; in 1784 he applied his 20-foot reflector, and made it a beautiful cluster of extremely compressed stars, resembling Messier's No. 53. He estimated its profundity to be of the 243rd order.

John Herschel (1847): h 3659.

h 3659 = M. 10 = h. 1972
Sweep 608 (July 15, 1835)
RA 16h 48m 13.4s, NPD 93d 48' 35" (1830.0) [Right Ascension and North Polar Distance]
Glob. Cl.; fine, L; R; B; g m b M; diam 5'; with stragglers, several of which are of large sizes, to about 12' diam; all resolved into st 11....15 m, very comp.
Globular Cluster; fine, large; round; bright; gradually much brighter toward the middle; diameter 5'; with stragglers, several of which are of large sizes [bright magnitudes], to about 12' diameter; all resolved into stars of 11th to 15th magnitude, very compressed.

Lord Rosse

John Herschel, General Catalogue: GC 4256.

GC 4256 = h 1972 = h 3659 = M10.
RA 16h 49m 47.6s, NPD 93d 52m 6.8s (1860.0) [Right Ascension and North Polar Distance]
!; Glob. Cl.; B; vL; R; gvmbM; rrr; st 10...15 7 observations by W. & J. Herschel.
Remarkable; globular cluster; bright; very large; round; gradually very much brighter toward the middle; well resolved; stars from 10th to 15th magnitude.

Huggins

[Further Observations on the Spectra of some Nebulae, with a Mode of determining the Brightness of these Bodies. Phil. Trans. Roy. Soc., Vol. 156 (1866), p. 381-397; here p. 390]
[No. [GC] 4256. 10 M. R.A. 16h 49m 47s.6. N.P.D. 93d 52' 6".8. Cluster; bright; well resolved.]
"The most important stars take a spiral arrangement." - Lord Oxmantown [Rosse]
Spectrum continuous.

Dreyer: NGC 6254.

NGC 6254 = GC 4256 = h 1972 = h 3659. M 10.
RA 16h 49m 47s, NPD 93d 52.7m (1860.0) [Right Ascension and North Polar Distance]
! Glob. Cl., B, vL, R, gvmbM, rrr, st 10...15; = M10
Remarkable globular cluster, bright, very large, round, gradually very much brighter toward the middle, well resolved, stars from 10th to 15th magnitude.

Curtis

[Descriptions of 762 Nebulae ans Clusters photographed with the Crossley Reflector. Publ. Lick Obs., No. 13, Part I, p. 9-42]
NGC 6254, RA=16:51.4, Dec=- 3:57. Fine, bright globular cluster; diameter 8'; central brighter part about 2'. 0 s.n.