Messier 99

Discovered by Pierre Méchain on March 15, 1781.

Messier: M99.

April 13, 1781. 99. 2h 07m 41s (181d 55' 19") +15d 37' 12"
Nebula without star, of a very pale light, nevertheless a little clearer than the preceding [M98], situated on the northern wing of Virgo, & near the same star, no. 6, of Comae Berenices. The nebula is between two stars of seventh & of eighth magnitude. M. Méchain saw it on March 15, 1781.

William Herschel

[Unpublished Observations of Messier's Nebulae and Clusters. Scientific Papers, Vol. 2, p. 660]
1787, Jan. 14 (Sw. 691). vB. vL. vgmbM. [very bright, very large, very gradually much brighter to the middle], and the brightness taking up a great space.

John Herschel (1833): h 1173.

h 1173 = M99.
Sweep 421 (April 26, 1832)
RA 12h 10m 9.9s, NPD 74d 38' 36" (1830.0) [Right Ascension and North Polar Distance]
Not v B; R; v g b M; 5' diam
Not very bright; round; very gradually brighter toward the middle; 5' diameter.

Sweep 422 (April 28, 1832)
RA 12h 10m 10.0s, NPD 74d 38' 34" (1830.0)
p B; v L; R; g b M; r; 5' diam
Pretty bright; very large; round; gradually brighter toward the middle; mottled; 5' diameter.

Sweep 419 (April 23, 1832)
RA 12h 10m 10.8s:, NPD 74d 36' 55": (1830.0)
B; R; g b M; r; 5' diam
Bright; round; gradually brighter toward the middle; mottled; 5' diameter.

Sweep 418 (April 21, 1832)
...., NPD 74d 46' 56":: (1830.0)
B; L; R; g b M. Seen through cloud
Bright; large; round; gradually brighter toward the niddle. Seen through cloud.

Smyth

[from his description of H I.35 = NGC 4216, his No. CCCCXXXVIII (438)]
Nearly 3' following this, and 1deg 1/4 to the north, is 99 M., a large round nebula, which, tough pale, is well defined in my instrument.

Lord Rosse

[Phil. Trans. 1850, p. 499-514, drawing on Plate XXXV, fig. 2]
[p. 505] In the following spring [of 1846] an arrangement, also spiral but of a different character [than in M51], was detected in 99 Messier, Plate XXXV. fig 2. This object is also easily seen, and probably a smaller instrument, under favourable circumstances, would show everything in the sketch. ...
[p. 509] Plate XXXV. figs. 1 and 2 are seen on a scale of half an inch to a minute; ...
Plate XXXV, fig. 2, H. 1173. - This nebula has been repeatedly observed with the 6-feet instrument.
March 11, 1848. - Spiral with a bright star above ; a thin portion of the nebula reaches across this star and some distance past it. Principal spiral at the bottom, and turning toward the right.
March 20, 1848. - Spirality very evident, though night bad: nebula not traced to upper star.
April 16, 1849. - Took measures of the stars 1, 2.
April 17, 1849. - Took measures of the stars 1, 2, 3, 4 from the nucleus; they are as follows:

  No.    Mean of     No. of   Greatest  Mean of  No. of   Greatest
       observation   obser-  difference  obser-  obser-  difference
       of position   vations  between   vations  vations  between
        from north            mean and  of dis-           mean and
       in direction           observa-   tance.           observa-
         n.f.s.p.               tion.                      tion.
  

           d  '                 d  '        "                " 
  1.      34  1        1       ......    2 54.6    2         9.6
  2.      80 35        2        0 18     1 46.3    3        14.4
  3.     117  3        3        0 23     1 48.4    4        13.6
  4.     177 57        1       ......    2 48.1    1
  

Three very minute stars in the eye-sketch have not been inserted, not having been measured.

John Herschel, General Catalogue: GC 2838.

GC 2838 = h 1173 = M99.
RA 12h 11m 41.8s, NPD 74d 48' 7.6" (1860.0) [Right Ascension and North Polar Distance]
!!; (H,h) B; L; R; gbM; r (L) 3-branched spiral. 6 observations by W. & J. Herschel.
Very remarkable; (W. & J. Herschel) bright; large; round; gradually brighter toward the middle; mottled; (Lassell, actually Rosse) 3-branched spiral.
Remark: Figure in P.T. 50 [Rosse 1850], plate xxxv., fig. 2.

Lassell

[Memoirs of the Royal Astronomical Society, Vol. XXXVI (36)]
[Drawing on Plate IV, Fig. 16]

Vogel

[Dr. H.C. Vogel: Positionsbestimmungen von Nebelflecken und Sternhaufen zwischen +9d 30' und +15d 30' Decl. Leipzig, 1876]
[Drawing on Plate I, Fig. 8]

Dreyer (1877)

GC 2838, h. 1173 [M 99]. Drawings in Lassell, Plate IV, Fig. 16, and in Vogel, Plate I, Fig. 8.

Dreyer: NGC 4254.

NGC 4254 = GC 2838 = h 1173; Méchain, M 99.
RA 12h 11m 43s, NPD 74d 48.2' (1860.0) [Right Ascension and North Polar Distance]
!! (H,h) B, L, R, gbM, r, (R & L) 3-branched spiral; = M99
Very remarkable, (W. & J. Herschel) bright, large, round, gradually brighter toward the middle, mottled, (Rosse and Lassell) 3-branched spiral.
Remark: Figures in P.T. 50 [Rosse 1850], plate XXXV, fig. 2; Lass 2 [Lassell, Memoirs R.A.S. vol. xxxvi], plate IV, fig. 16; Vogel ["Positionsbestimmungen von Nebelflecken und Sternhaufen zw. +9d 30' und +15d 30' Decl." (Leipziger Beob. Band I)], plate I, fig. 8.

R.H. Allen

[under Coma Berenices] Near Fl[amsteed]. 6 is the Pin-wheel Nebula, N.G.C. 4254, 99 M., one of the pyrotechnics in the sky.

Curtis

[Descriptions of 762 Nebulae and Clusters photographed with the Crossley Reflector. Publ. Lick Obs., No. 13, Part I, p. 9-42]
NGC 4254, RA=12:13.7, Dec=+14:59. [Publ. Lick Obs.] Vol. VIII, Plate 32. A very bright, approximately round spiral 4.5' in diameter. Nucleus almost stellar. There are two main whorls, rather open, which show many almost stellar condensations. M. 99. 47 s.n.