Messier 94

Discovered on March 22, 1781 by Pierre Méchain.

Messier: M94.

March 24, 1781. 94. 12h 40m 43s (190d 10' 46") +42d 18' 43"
Méchain: (190d 09' 38") +42d 18' 50"
Nebula without star, above the Heart of Charles [Alpha Canum Venaticorum], on the parallel of the star no. 8, of sixth magnitude of the Hunting Dogs [Canes Venatici], according to Flamsteed: In the center it is brilliant & the nebulosity [is] a bit diffuse. It resembles the nebula which is below Lepus, No. 79; but this on is more beautiful & brighter: M. Méchain has discovered this one on March 22, 1781. (diam. 2.5')

William Herschel

[Unpublished Observations of Messier's Nebulae and Clusters. Scientific Papers, Vol. 2, p. 660]
1787, March 18 (Sw. 717). Very brilliant, a large, luminous nucleus of more than 20" diameter with faint chevalure and branches extending 6 or 8'.
1787, Apr. 9 (Sw. 725). Very brilliant, with much F. [faint] nebulosity on the sp. [south predecing, SW] and more on the f. [following, E] side.

John Herschel (1833): h 1456.

h 1456 = M94.
Sweep 155 (May 12, 1828)
RA 12h 42m 51.9s, NPD 47d 57' 2" (1830.0) [Right Ascension and North Polar Distance]
vB; L; vsmbM, almost up to a nipple-like nucleus. Not resolved, but strong twilight. (See fig. 41)
Very bright; large; very suddenly much brighter toward the middle, almost up to a nipple-like nucleus. Not resolved, but strong twilight. (See fig. 41)

Sweep 248 (April 12, 1830)
RA 12h 42m 51.4s, NPD 47d 56' 28" (1830.0)
B; L; R or l E; s m b M to nucleus 15" in diam and = a * 8 m, well defined, but not stellar. The nebula 2' diam.
Bright; large; round or little extended; suddenly much brighter toward the middle to nucleus 15" in diameter and equal [in brightness] to a star of 8 m, well defined, but not stellar. The nebula 2' diameter.

Sweep 335 (March 18, 1831)
RA 12h 42m 52.0s, NPD 47d 56' 26" (1830.0)
eB; R; v s v m b M to a nucleus = in its impression to the eye to a * 9m, but which will not bear illuminating more than 11m; diam of neb = 2 1/2'.
Extremely bright; round; very suddenly very much brighter toward the middle to a nucleus equal in its impression to the eye to a star of 9m, but which will not bear illuminating more than 11m; diam of neb is 2 1/2'.

Sweep 150 (May, 1828)
RA 12h 42m 52.2s, NPD 47d 56' 42" (1830.0)
v B; R; p s v m b M, to a nipple; with 240, r; glimpses of stars seen. A fine object. 90" or 2' in diam.
Very bright; round; pretty suddenly very much brighter toward the middle, to a nipple; with magnification 240, mottled; glimpses of stars seen. A fine object. 90" or 2' in diameter.

Sweep 151 (May 6, 1828)
RA 12h 42m 52.9s, NPD 47d 56' 51" (1830.0)
The central B part (10" diam) equals a * 9m, e compressed
The central bright part (10" diameter) equals a star of 9m, extremely compressed.

Sweep 73 (April 28, 1827)
Viewed. v B; v s m b M; 4' diam. Not resolved but resolvable. (A very interesting object, being a neb v s m b M on a great scale.)
Viewed. Very bright; very suddenly much brighter toward the middle; 4' diameter. Not resolved but resolvable [mottled]. (A very interesting object, being a nebula very suddenly much brighter toward the middle on a great scale.)

[Appendix]

[Figure on Plate XIII, Figure 41, No. 1456, M. 94, RA 12h 42m 52s, NPD 47d 57']

Smyth: CCCCLIX [459]. M94.

CCCCLIX. 94 M. Canum Venaticorum.
AR 12h 43m 22s, Dec N 41d 59'.7
Mean Epoch of Observation: 1834.32 [April 1834]
A large bright nebula discovered by Méchain, in 1781, immediately preceding the crown on Charles' Heart [Cor Carolis, Alpha CVn]. It is a fine pale-white object, with evident symptoms of being a compressed cluster of small stars. It brightens towards the middle, and the gradual augmentation of intensity from the margin tothe centre of this apparently orbicular object, is a direct proof of the real sphericity of the stellar mass. There are several small stars in the field, of which one in the sf [south following, SE] quadrant is double. Differentiated with the bright star Cor Caroli, from which it is but 2deg 1/2 in the north-by-west.

John Herschel, General Catalogue: GC 3258.

GC 3258 = h 1456 = M94.
RA 12h 44m 17.2s, NPD 48d 6' 31.8" (1860.0) [Right Ascension and North Polar Distance]
vB; L; iR; vsvmbMBN; r. 10 observations by W. & J. Herschel.
Very bright; large; irregularly round; very suddenly very much brighter toward the middle where there is a bright nucleus; mottled.
Remark: Figure in P.T. 33 [JH 1833], plate v., fig. 41.

Lassell

[Memoirs of the Royal Astronomical Society, Vol. XXXVI (36)]
[Drawing on Plate V, Fig. 25]

Dreyer (1877)

GC 3258, h. 1456 [M 94]. Drawings in Lassell, Plate V, Fig. 25.

Dreyer: NGC 4736.

NGC 4736 = GC 3258 = h 1456; Méchain, M 94.
RA 12h 44m 17s, NPD 48d 7.0' (1860.0) [Right Ascension and North Polar Distance]
vB, L, iR, vsvmbMBN, r; = M94
Very bright, large, irregularly round, very suddenly very much brighter toward the middle where there is a bright nucleus; mottled.
Remark: Figure in P.T. 33 [JH 1833], plate XIII, fig. 41; Lass 2 [Lassell, Memoirs R.A.S. vol. xxxvi], plate V, fig. 25.

Curtis

[Descriptions of 762 Nebulae and Clusters photographed with the Crossley Reflector. Publ. Lick Obs., No. 13, Part I, p. 9-42]
NGC 4736, RA=12:46.2, Dec=41:40. [Publ. Lick Obs.] Vol. VIII, Plates 43 and 44. M. 94. A beautiful object. From the very bright, large nucleus spring many bright, closely packed whorls, forming a bright inner oval 2'x1.5' in p.a. about 110deg. These inner whorls show many stellar condensations, whose sharpness and proximity to the nucleus would seem to make this one of the most favorable examples known for the investigation of motions in spirals. Fainter, closely packed, rather uniform outer whorls bring the nebula to a size of 5'x3.5'. 17 s.n.