Messier 61

Discovered on May 5, 1779 by Barnabus Oriani.
Indepedently discovered on May 11, 1779 by Charles Messier (who had also seen it on May 5).

Messier: M61.

May 11, 1779. 61. 12h 10m 44s (182d 41' 05") +5d 42' 05"
Nebula, very faint & difficult to perceive. M. Messier mistook this nebula for the Comet of 1779, on the 5th, 6th & 11th of May; on the 11th he recognized that this was not the Comet, but a nebula which was located on its path & in the same point [place] of the sky.

Oriani

May 5, 1779
Very pale and looking exactly like the comet [1779 Bode, C/1779 A1].

William Herschel: H I.139.

I.139. April 17, 1785.
eB. vBN. r. 6 or 7' dia.
Extremely bright. Very bright nucleus. Resolvable [mottled, not resolved]. 6 or 7' diameter.

John Herschel (1833): h 1202.

h 1202 = M61 = H I.139.
Sweep 141 (April 7, 1828)
RA 12h 13m 12.8s, NPD 84d 34' 55" (1830.0) [Right Ascension and North Polar Distance]
B; v L; v s b M to a * 11m, with a F atmosphere about it. This nebula is probably identical to I. 139. (See fig. 69.)
Bright; very large; very suddenly brighter toward the middle to a star of 11m, with a faint atmosphere about it. This nebula is probably identical to H I. 139. (See fig. 69.)

Sweep 142 (April 9, 1828)
RA 12h 13m 13.7s, NPD 84d 34' 56" (1830.0)
B nucleus in a v F atmosph 2' diam, gradually fading away
Bright nucleus in a very faint atmosphere of 2' diameter, gradually fading away.

Sweep 143 (April 10, 1828)
Viewed; v faintly bicentral. The two nuclei 90" dist pos 45..50 deg nf.
Viewed; very faintly bicentral. The two nuclei are 90" distant in position angle 45..50 deg north following [NE].

[Appendix]

[Figure on Plate XV, Figure 69, No. 1202, M. 61 = I. 139, RA 12h 13m 13s, NPD 84d 35']
Plate XV. Fig. 68-79. - Double Nebulae.

Smyth: CCCCXLII [442]. M61.

CCCCXLII. 61 M. Virginis.
AR 12h 13m 45s, Dec N 5d 21'.6
Mean Epoch of Observation: 1837.26 [Feb 1837]
A large pale-white nebula, between the Virgo's shoulders. This is a well defined object, but so feeble as to excite surprise that Messier detected it with his 3 1/2 foot telescope in 1779. Under the best action of my instrument it blazes towards the middle; but in H. [John Herschel]'s reflector it is faintly seen to be bicentral [an illusion caused by the bar], the nuclei 90" apart, and lying sp [south preceding, SW] and nf [north following, NE]. It is preceded by four telescopic stars, and followed by another. Differentiated with the following object [17 Virginis], from which it bears about south by west, and is within a degree's distance.
This object is an outlier of a vast mass of discrete but neighboring nebulae, the spherical forms of which are indicative of compression.

John Herschel, General Catalogue: GC 2878.

GC 2878 = h 1202 = H I.139 = M61.
RA 12h 14m 45.1s, NPD 84d 44' 55.3" (1860.0) [Right Ascension and North Polar Distance]
vB; vL; vsbM*; biN. 5 observations by W. & J. Herschel.
Very bright; very large; very suddenly much brighter toward the middle which is starlike; binuclear.
Remark: 2878 = h. 1202 = I.139 = M.61. Discovered by Oriani. N.B. The first discoverers of the nebulae in Messier's list, when not Messier himself, are mentioned by M. Auwers in his catalogue of those nebulae (pp. 66-71), except in the cases of Oriani's nebulae, M.14?, 18?, 35?, 61, 67 [Actually, Oriani did not discover M14, 18, 35 and 67 before Messier].
Figure in P.T. 33 [JH 1833], plate vii., fig. 69.

Dreyer: NGC 4303.

NGC 4303 = GC 2878 = h 1202 = H I.139; Oriani, M 61.
RA 12h 14m 46s, NPD 84d 45.0' (1860.0) [Right Ascension and North Polar Distance]
vB, vL, vsbM*, biN; = M61
Very bright, very large, very suddenly much brighter toward the middle which is starlike, binuclear.
Remark: Figure in P.T. 33 [JH 1833], plate XV, fig. 69; P.T. 61 [Lord Rosse 1861], plate XXVII, fig. 21.

Curtis

[Descriptions of 762 Nebulae and Clusters photographed with the Crossley Reflector. Publ. Lick Obs., No. 13, Part I, p. 9-42]
NGC 4303, RA=12:16.8, Dec=+ 5: 2. [Publ. Lick Obs.] Vol. VIII, Plate 34. M. 61. Nearly round; 6' in diameter; very bright. A beautiful spiral, with a very bright, almost stellar nucleus, and many almost stellar condensations in its open, somewhat irregular whorls. 40 s.n.