Messier 97

Discovered on Feb 16, 1781 by Pierre Méchain.

Messier: M97.

March 24, 1781. 97. 11h 01m 15s (161d 18' 40") +56d 13' 30"
(actually, an erroneous "A" for "Australis", thus "Southern dec" appears in the printed version of the Catalog in the Connoissance des Temps, while not in Messier's preliminary, handwritten notes)
Nebula in the great Bear [Ursa Major], near Beta: It is difficulat to see, reports M. Méchain, especially when one illuminates the micrometer wires: its light is faint, without a star. M. Méchain saw it the first time on Feb 16, 1781, & the position is that given by him. Near this nebula he has seen another one, [the position of] which has not yet been determined [M108], and also a third which is near Gamma of the Great Bear [M109 near Gamma Ursae Majoris]. (diam. 2')

(The two nebulae mentioned here have been entitled M108 and M109 by Owen Gingerich in 1953, see the additional Messier objects.)

William Herschel

[Astronomical Observations relating to the Construction of the Heavens.. Phil. Trans. (1811), p. 269-336, here p. 314, reprinted in Scientific Papers, Vol. 2, p. 485]
28. Of round Nebulae that are of an almost uniform Light. [..]
The arguments that the nebulous matter is in some degree opaque which is given in the 25th article, will receive considerable support from the appearance of the following nebulae; for they are not only round, that is to say the nebulous matter of which they are composed is collected into a globular compass, but they are also of a light which is nearly of an uniform intensity except just on the borders. I give these nebulae in two assortments (incl. M97).
Number 97 of the Connoissance is "A very bright, round nebula of about 3' in diameter; it is nearly of equal light throughout, with an ill defined margin of no great extent."

[Astronomical Observations for Ascertaining the Distances of Clusters of Stars, &c., Phil. Trans. Vol. CVIII (1818), p. 429-470, here p. , reprinted in Scientific Papers, Vol. 2, p. 601] The 97th of the Connoissance.
"1799, 7 feet finder. The object is not visible in it."
"1789, 20 feet telescope; considerably bright, globular, of equal light throughout, with a diminishing border of no great extent. About 3 minutes in diameter."
"1805, large 10 feet telescope. The constellation being too low it had the appearance of a faint nebula."
From the observation with the 20 feet telescope, it appears that the profundity of this object is beyond the gauging power of that instrument; and as it must be sufficiently distant to be ambiguos, it cannot be less than of the 980th order.

John Herschel (1833): h 838.

h 838 = M.97.
Sweep 324 (February 10, 1831)
RA 11h 4m 49.4s, NPD 34d 3' 52" (1830.0) [Right Ascension and North Polar Distance]
A large uniform nebulous disc, diameter 19.0s of time in AR [RA]. Quite round, v B; not sharply defined, but yet very suddenly fading away to darkness. A most extraordinary object. See fig. 32.
A large uniform nebulous disc, diameter 19.0s of time in AR [RA]. Quite round, very bright; not sharply defined, but yet very suddenly fading away to darkness. A most extraordinary object. See fig. 32.

[Appendix]

[Figure on Plate X, Fig. 32, No. 838, M. 97, RA 11h 4m 49s, NPD 34d 4']

Smyth: CCCCII [402]. M97.

CCCCII. 97 M. Ursae Majoris.
AR 11h 05m 24s, Dec N 55d 52'.2
Mean Epoch of Observation: 1837.16 [Mar 1837]
[with drawing]
A large planetary nebula, or globular collection of nebulous matter, found by M. [Messier] in 1781, on the Great Bear's flank, with several stars in the field, one of which is pretty close. It lies about 2deg to the south-east of Beta, Merak, and just south of an imaginary line from Beta to Gamma. This very singular object is circular and uniform, and after a long inspection looks like a condensed mass of attenuated light, seemingly of the size of Jupiter. The mean apparent place was obtained by a differentiation with that of Psi Ursae Majoris, and this diagram was sketched. Sir William Herschel discovered this orb in 1789, and found it a globular body of equal light throughout: he also say, "From the observation of the 20-foot telescope, it appears that the profundity of this object is beyond the gauging power of that instrument; and as it must be sufficiently distant to be ambiguous, it cannot well be less than of the 980th order." The 980th order!

Lord Rosse

[Phil. Trans. 1844, p. 321-324, on his observation with his 3-feet (36-inch) aperture telescope]
In fig. 32 [of JH (1833)] we also find a star in the centre.

Webb

Large pale plan. neb.; very remarkable object. h. [John Herschel], 2'40" [diameter], which at distance of 61 Cygni only, would equal 7 times orbit of Neptune. He saw light nearly equable, though with softened edge, and faintly bicentral. E. of Rosse, on the contrary, two large perforations (whence it has been called the `Owl Neb.'), and an indistinct spiral structure. Before 1850, there was a star in each opening; since, one only.

John Herschel, General Catalogue: GC 2343.

GC 2343 = h 838 = M97.
RA 11h 6m 34.8s, NPD 34d 13' 38.2" (1860.0) [Right Ascension and North Polar Distance]
!!; PN; vB; vL; R; vvg,vsbM PN; 19s.0 d. 4 observations by W. & J. Herschel.
Very remarkable; planetary nebula; very bright; very large; round; very very gradually, then very suddenly brighter toward the middle of this planetary nebula; 19.0s [of time; about 150"] diameter.
Remark: Figures in: P.T. 33 [JH 1833], plate ii, fig. 32; P.T. 50 [Lord Rosse 1850], plate xxxvii, fig. 11.

Huggins

[Further Observations on the Spectra of some Nebulae, with a Mode of determining the Brightness of these Bodies. Phil. Trans. Roy. Soc., Vol. 156 (1866), p. 381-397; here p. 388]
[No. 2343. 838 h. 97 M. RA 11h 6m 34s.8. N.P.D. 34d 13' 38".2. Planetary; very bright; very large; round; very gradually, very suddenly brighter in the middle.]
"A large uniform nebulous disk, diameter 19s.0 in R.A. Quite round, very bright, not sharply defined, but yet very suddenly fading away to darkness." - Sir John Herschel (*).
"Two stars considerably apart in the central region, dark peniumbra round each spiral arrangement, with stars as apparent centres of attraction. Stars sparkling in it; resolvable." - Lord Rosse (+)
"Two stars were easily seen in this nebula formerly; since 1850 only one has been seen. Not observed since April 1864." - Lord Oxmantown.
The spectrum consists of the two brighter lines usually present. A continuous spectrum is doubtful. Once or twice a very faint continuous spectrum was suspected. - June 1866.

---

(*) Philosophical Transactions, 1833, p. 402, also Plate X. fig. 32.
(+) Ibid. 1850, p. 513, and plate XXXVII. fig 2.

Dreyer: NGC 3587.

NGC 3587 = GC 2343 = h 838; Méchain, M 97.
RA 11h 6m 40s, NPD 34d 13.3' (1860.0) [Right Ascension and North Polar Distance]
!!, PN , vB, vL, R, vvg, vsbM, 150" d; = M97
Very remarkable, planetary nebula, very bright, very large, round, very very gradually, then very suddenly brighter toward the middle, 150" diameter.
Remark: Figures in: P.T. 33 [JH 1833], plate X, fig. 32; P.T. 50 [Lord Rosse 1850], plate XXXVII, fig. 11.

Curtis

[Descriptions of 762 Nebulae ans Clusters photographed with the Crossley Reflector. Publ. Lick Obs., No. 13, Part I, p. 9-42]
NGC 3587, RA=11: 9.0, Dec=+55:34. Planetary. The ``Owl'' Nebula, [Publ. Lick Obs.] Vol. VIII, Plate 27. 107 s.n.

[The Planetary Nebulae. Publ. Lick Obs., No. 13, Part III, p. 55-74]
[with Lick b/w photo, Fig. 23]
NGC 3587; 11h 9.0m; +55d 34'
The ``Owl'' Nebula. Enlarged 4.0 times from a negative of 4h 12m exposure time. The central star is visual magn. 14 (Burnham), and about 12m photographically. The brighter central oval lies in p.a. 12deg, and the diameter along this line is 199"; at right angles to this direction it is 203" in diameter to outside the whorls. Aside from the outer whorls all structural details are very vague and indistent. Rel. Exp. 100.