Messier 25

Discovered 1745-46 by Philippe Loys de Chéseaux.
Independently rediscovered by Charles Messier on June 20, 1764.
In the catalogs of Bode, Smyth, and Webb, but not in John Herschel's and the NGC catalogs.
According to Kenneth Glyn Jones, rediscovered by Julius Schmidt in 1866.
Added to the IC catalog from data by Solon I. Bailey in 1908.

Messier: M25.

June 20, 1764. 25. 18h 17m 40s (274d 25' 00") -19d 05' 00"
A cluster of small stars in the neighborhood of the two previous clusters [M23 and M24], between the head & the end of the bow of Sagittarius: the nearest known star to this cluster is 21 Sagittarii, 6th magnitude, according to Flamsteed. The stars of this cluster are seen with difficulty with an ordinary telescope of 3.5-foot [FL]; no nebulosity can be seen. Its position has been determined from Mu Sagittarii. (diam. 10')

[Mem. Acad. for 1771, p. 445 (first Messier catalog)]
In the same night [June 20 to 21, 1764], I have determined the position of another star cluster in the vicinity of the two preceding, between the head & the extremity of the bow of Sagittarius, & almost on the same parallel as the two others: the closest known star is that of the sixth magnitude, the twenty-first of Sagittarius, in the catalog of Flamsteed: this cluster is composed of small stars which one sees with difficulty with an ordinary [non-achromatic] refractor of 3 feet: it doesn't contain any nebulosity, & its extension may be 10 minutes of arc. I have determined its position by comparing with the star Mu Sagittarii; its right ascension has been found at 274d 25', & its declination at 19d 5' south.
[p. 456] 1764.Jun.20. RA: 274.25. 0, Dec: 19. 5. 0.A, Diam: 0.10. Cluster of small stars in the vicinity of the two preceding, between the head & the extremity of the bow of Sagittarius: this cluster doesn't contain any nebulosity.

De Chéseaux: De Ch. No. 5.

Another one between the bow and the head of Sagittarius, of which RA is about 274d 17' and southern declination is 19d 11' 30".

Bode: Bode 56.

A nebulous star cluster.

Bode (1782): 162 Sagittarii.

[From: Vorstellung der Gestirne auf XXXIV Kupfertafeln (Introduction to the Stars on 34 Copper Plates), 1782. Here p. 25, plate 20]
Sgr 79, after Tobias Mayer. RA: 274:37 [18:18.5], Dec: -19:02. In the place of this stars, Messier places a small cluster of stars, No. 162.
Sgr 162, after Messier. RA: 274:39 [18:18.6], Dec: -19:05. Small Star Cluster.

Caroline Herschel

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

William Herschel:

[Unpublished Observations of Messier's Nebulae and Clusters. Scientific Papers, Vol. 2, p. 652. Dreyer's remark: Not in NGC, 18h 23m, 109d 2' for 1860]
1783, July 30. Very large [bright] stars and some small [faint] ones; I counted 70, and there are many more within no considerable extent.

Smyth: DCLI [651]. M25.

DCLI [651]. 25 M. Sagittarii.
AR 18h 22m 14s, Dec S 19d 10'.2
Mean Epoch of Observation: 1836.60 [Aug 1836]
A loose cluster of large and small stars in the Galaxy, between the Archer's head and Sobieski's shield; of which a pair og 8th magnitudes, the principle of a set something in the form of a jew's harp, are above registered. The gathering portion of the group assumes an arched form, and is thickly strewn in the south, on the upper part, where a pretty knot of minute glimmerers occupies the center, with much star-dust around. It was discovered in 1764 by Messier, and estimated by him at 10' in extent: it is 5 deg to the north-east of Mu Sagittarii, and nearly on the parallel of Beta Scorpii, which glimmers far away in the west.

Webb

Coarse and brilliant. Not in GC.

Julius Schmidt (1866)

According to Kanneth Glyn Jones, IC 4725 (M25) was added to the IC on the ground of its rediscovery by Julius Schmidt 1866, and entered in 1908 with a position obtained by Bailey.
The present author [hf] couldn't yet verify the presumable rediscovery by Julius Schmidt, despite studies of the AN of that years, among others. OTOH, as can be seen above, it was wellknown to Smyth and Webb and contained in the considerably widespread catalogs of Messier and Bode. - Jan-29-2005

Dreyer (IC I)

[Introduction to the IC I catalog]
Two clusters in MESSIER's catalogue do not occur in the New General Catalogue, and may perhaps be mentioned here. They are (for 1860):

    M. 25  18h 23m 17s  109d  2'.0  Cl of S st [cluster of small (faint) stars]
    M. 48   8h  6m 54s   91d 32'.1  Cl of S st [cluster of small (faint) stars]

Bailey:

RA 18:25.8, Dec -19:19 (1900.), Diam 25', 50 st 9-12, class D2 [Fairly condensed irregular cluster of stars of different magnitudes]
Cluster, fairly condensed.

Dreyer: IC 4725

IC 4725. M 25, Bailey.
RA 18h 23m 26s, NPD 109d 20' (1860.0) [Right Ascension and North Polar Distance]
RA 18h 25m 48s, NPD 109d 19' (1900.0)
Cl, pC; = M25
Cluster, pretty compressed.