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[M 66]

Messier 66

Observations and Descriptions

Discovered on March 1, 1780 by Charles Messier.

Messier: M66.
March 1, 1780. 66. 11h 08m 47s (167d 11' 39") +14d 12' 21"
`Nebula discovered in Leo; its light is very faint & it is very close to the preceding [M65]: They both appear in the same field [of view] in the refractor. The comet of 1773 & 1774 has passed between these two nebulae on November 1 to 2, 1773. M. Messier didn't see them at that time, no doubt, because of the light of the comet.'

William Herschel
[Unpublished Observations of Messier's Nebulae and Clusters. Scientific Papers, Vol. 2, p. 658]
1784, Apr. 12 (Sw. 188). A vB. mE. [very bright, much extended] nebula of irregular figure; the extension is chiefly in the direction of the meridian and the greatest brightness near the middle.

John Herschel (1833): h 857.
h 857 = M66.
Sweep 22 (March 13, 1826)
RA 11h 11m 16.9s, NPD 76d 5' 47" (1830.0) [Right Ascension and North Polar Distance]
v B; v L; s b M; 3'l, 2'br; E 60deg n p to s f in direction of 2 st 10m, p.
Very bright; very large; suddenly brighter toward the middle; 3' long, 2' broad; extended in position angle 60deg north preceding to south following [NW to SE] in direction of 2 stars of 10m, which are preceding [to the West].

Sweep 2 (April 10, 1825)
..., NPD 76d 3' +/- (1830.0)
p B; g b M; E towards 2 stars n p
Pretty bright; gradually brighter toward the middle; extended towards 2 stars which are north preceding [to the NW].

Sweep 3 (April 11, 1825)
..., NPD 76d 5' 32" (1830.0)
F; g b M; E; has 2 stars n p
Faint; gradually brighter toward the middle; extended; has 2 stars north preceding [to the NW].

h 875 = Nova. [= M66?]
RA 11h 14m 11.5s, NPD 76d 5' 3" (1830.0)
Sweep 338 (April 4, 1831)
v L; 6'l, 4'br; first v g, then v s v m b M.

Sweep 340 (April 6, 1831)
Viewed; v B; v L; v s b M. (See fig. 54).


[Figure on Plate XIV, Figure 54, No. 875, Nova, RA 11h 14m 12s, NPD 76d 5']
Plate XIV. Figs. 50 .... 67. [includes I.43 (M104), V.8 (NGC 3628), V.1 (NGC 253), M65, h 875 (M66?), V.43 (M106), I.156 (NGC 1023), I.210 (NGC 4346), IV.42 (NGC 676), I,109 (NGC 1201), II.600 (NGC 7640), II.280 (NGC 2695), IV.30 (NGC 4861), I.55 (NGC 7479), IV.2 (NGC 2261), IV.66 (NGC 2701), III.602 (NGC 4571), and I.143 (NGC 4900)] - Long nebulae. The general form of elongated nebulae is elliptic, and their condensation towards the centre is almost invariably such as would arise from the superposition of luminous elliptic strata, increasing in density towards the centre. [..]

Smyth: CCCCX [410]. M66.
CCCCX. 66 M. Leonis.
AR 11h 11m 48s, Dec N 13d 52'.4
Mean Epoch of Observation: 1835.31 [April 1835]
[with a drawing of M65 and M66]
A large elongated nebula, with a bright nucleus, on the Lion's haunch, trending np [north preceding, NW] and sf [south following, SE]; this beautiful specimen of perspective lies just 3deg south-east of Theta Leonis. It is preceded at about 73s by another of a similar shape, which is Messier's No. 65, and both are in the field at the same time, under a moderate power, together with several stars. They were pointed out by Méchain to Messier in 1780, and they appeared faint and hazy to him [Actually, these are Messier's original discoveries]. The above is their appearance in my instrument.
These inconceivably vast creations are followed, exactly on the same parallel, ar Delta AR=174s, by another elliptical nebula of even a more stupendous character as to apparent dimensions. It was discovered by H. [John Herschel], in sweeping, and is No. 875 in his Catalogue of 1830 [actually, probably an erroneous position for re-observed M66].
The two preceding of these singular objects were examined by Sir William Herschel, and his son [JH] also; and the latter says, "The general form of elongated nebulae is elliptic, and their condensation towards the centre is almost invariably such as would arise from the superposition of luminous elliptic strata, increasing in density towards the centre. In many casesthe increase of density is obviously attended with a diminution of ellipticity, or a nearer approach to the globular form in the central than in the exterior strata." He then supposes the general constitution of those nebulae to be that of oblate spheroidal masses of every degree of flatness from the sphere to the disk, and of every variety in respect of the law of their density, and ellipticity towards the centre. This must appear startling and paradoxical to those who imagine that the forms of these systems are maintained by forces identical with those which determine the form of a fluid mass in rotation; because, if the nebulae be only clusters of discrete stars, as in the greater number of cases there is every reason to believe them to be, no pressure can propagate through them. Consequently, since no general rotation of such a system as one mass can be supposed, Sir John suggests a scheme which he shows is not, under certain conditions, inconsistent with the law of gravitation. "It must rather be conceived," he tells us, " as a quiescent form, comprising within its limits an indefinite magnitude of individual constituents, which, for aught we can tell, may be moving one among the other, each animated by its own inherent projectile force, and deflected into an orbit more or less complicated, by the influence of that law of internal gravitation which may result from the compounded attractions of all its parts."

John Herschel, General Catalogue: GC 2377.
GC 2377 = h 857 = h 875 = M66.
RA 11h 12m 48.3s, NPD 76d 15' 17.5" (1860.0) [Right Ascension and North Polar Distance]
B; vL; mE 150deg; mbM; 2 st np. 9 observations by W. & J. Herschel.
Bright; very large; much extended in position angle 150 degrees; much brighter toward the middle; 2 stars north preceding [NW].
Remark: 2377 = h. 857, h. 875; M. 66. No doubt these [2 h. entries] are the same. fig. 54 P.T. 1833 corroborates this identity. The accompanying stars and their positions agree entirely. The R.A. of h. 875, however, requires to be corrected by -3m, allowing the seconds and the P.D. observed in that observations their weight.
Figures in P.T. 33 [JH 1833], plate vi, fig. 54; P.T. 61 [Lord Rosse 1861], plate xxvi, fig. 16.

[Dr. H.C. Vogel: Positionsbestimmungen von Nebelflecken und Sternhaufen zwischen +9d 30' und +15d 30' Decl. Leipzig, 1876]
[Drawing on Plate I, Fig. 5]

Dreyer (1877)
GC 2377, h. 857 and h. 875 [M 66]. Drawings in Vogel, Plate I, Fig. 5.

Dreyer: NGC 3627.
NGC 3627 = GC 2377 = h 857 = h 875; M 66.
RA 11h 12m 56s, NPD 76d 14.5' (1860.0) [Right Ascension and North Polar Distance]
B, vL, mE 150deg, mbM, 2 st np; = M66
Bright, very large, much extended in position angle 150 degrees, much brighter toward the middle, 2 stars north preceding [NW].
Remark: Figures in P.T. 33 [JH 1833], plate XIV, fig. 54; P.T. 61 [Lord Rosse 1861], plate XXVI, fig. 16; Vogel ["Positionsbestimmungen von Nebelflecken und Sternhaufen zw. +9d 30' und +15d 30' Decl." (Leipziger Beob. Band I)], plate I, fig. 5.

[Descriptions of 762 Nebulae and Clusters photographed with the Crossley Reflector. Publ. Lick Obs., No. 13, Part I, p. 9-42]
NGC 3627, RA=11:15.0, Dec=+13:32. [Publ. Lick Obs.] Vol. VIII, Plate 28. A very bright, beautiful, spiral 8'x2.5' in p.a. 180deg. Bright, slightly elongated nucleus; the whorls are somewhat irregular and show numerous condensations. M. 66.
  • Observing Reports for M66 (IAAC Netastrocatalog)

    Hartmut Frommert
    Christine Kronberg

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    Last Modification: February 20, 2005