Messier 84

Discovered by Charles Messier on March 18, 1781.

Messier: M84.

March 18, 1781. 84. 12h 14m 01s (183d 30' 21") +14d 07' 01"
"Nebula without star, in Virgo; the center it is a bit brilliant, surrounded with a slight nebulosity: its brightness & its appearance resemble that of those in this Catalog, No.s 59 & 60."

William Herschel

[1811: PT Vol. 1811, p. 226-336; here p. 290-291]
12. Of the remarkable Situation of Nebulae.
The number of compound nebulae that have been noticed in the foregoing three articles [on multiple nebulae] being so considerable, it will follow, that it they owe their origin to the breaking up of some former extensive nebulosities of the same nature with those which have been shewn to exist at present, we might expect that the number of separate nebulae should far exceed the former, and that moreover these scattered nebulae should be found not only in great abundance, but also in proximity or continuity of each other, according to the different extents and situations of the former diffusions of such nebulous matter. Now this is exactly what by observation, we find to be the state of the heavens.
In the following seven assortments we have not less than 424 nebulae; [..]
(*) [1st assortment] See sixty-one nebulae. [including M84]

[Unpublished Observations of Messier's Nebulae and Clusters. Scientific Papers, Vol. 2, p. 659]
1784, Apr. 17 (Sw. 199). A bright nebula. [The only observation - Dreyer]

John Herschel (1833): h 1237.

h 1237 = M84.
Sweep 192 (May 4, 1829)
RA 12h 16m 26.2s, NPD 76d 10' 9" (1830.0) [Right Ascension and North Polar Distance]
v B; R; p s b M; 60"; r
Very bright; round; pretty suddenly brighter toward the middle; 60" [diameter]; mottled.

Smyth

[from the description of M88]
[has it in a chart]
.. "in the immediate nebulous neighborhood" of 88 Messier ..

John Herschel, General Catalogue: GC 2930.

GC 2930 = h 1237 = M84.
RA 12h 17m 57.6s, NPD 76d 20' 8.7" (1860.0) [Right Ascension and North Polar Distance]
vB; pL; R; psbM; r. 2 observations by W. & J. Herschel.
Very bright; pretty large; round; pretty suddenly brighter toward the middle; mottled.

Dreyer: NGC 4374.

NGC 4374 = GC 2930 = h 1237; M 84.
RA 12h 17m 58s, NPD 76d 20.2' (1860.0) [Right Ascension and North Polar Distance]
vB, pL, R, psbM, r; = M84
Very bright, pretty large, round, pretty suddenly brighter toward the middle, mottled.
Remark: 4374. GC 2932-40. Ld R [Lord Rosse] novae. "12 knots examined." h and H [J. & W. Herschel] have more than 12 nebulae between 12h 18m-21m and [PD] 76d to 77d, so there does not appear to have been sufficient reason for introducing these nine "novae" in the G.C.

Curtis

[Descriptions of 762 Nebulae and Clusters photographed with the Crossley Reflector. Publ. Lick Obs., No. 13, Part I, p. 9-42]
NGC 4374, RA=12:20.0, Dec=+13:27. Very bright; round, 1' in diameter. Center large. No spiral structure discernible.