Known to Al-Sufi about AD 905 and depicted AD 964.
Reported on a Dutch starmap of 1500.
Independently found and first observed with a telescope by Simon Marius on December 15, 1612.
Independently rediscovered by Hodierna before 1654.
(Flammarion reports that Messier added a note in his personal copy of the catalog by hand: `I have employed different instruments, especially an excellent Gregorian telescope of 30 feet FL, the large mirror 6 inches in diameter, magnification 104x. The center of this nebula appears fairly clear in this instrument without any stars appearing. The light gradually diminishes until it becomes extinguished. The former measurements were made with a Newtonian telescope of 4.5 feet FL, provided with a silk thread micrometer. Diameter 40'. August 3, 1764.')
[Mem. Acad. for 1771, p. 446-447 (first Messier catalog)]
The sky has been very good in the night of August 3 to 4, 1764; & the constellation Andromeda was near the Meridian, I have examined with attention the beautiful nebula in the girdle of Andromeda, which was discovered in 1612 by Simon Marius, & which has been observed since with great care by different astronomers, & at last by M. le Gentil who has given a very ample & detailed description in the volume of the Momoirs of the Academy for 1759, page 453, with a drawing of its appearance. I will not report here what I have written in my [observing] Journal: I have employed different instruments for examining that nebula, & above all an excellent Gregorian telescope of 30 pouces focal length, the large mirror having 6 pouces in diameter, & magnifying 104 times these objects: the middle of that nebula appeared rather bright with this instrument, without any appearance of stars; the light went diminishing up to extinguishing; it resembles two cones or pyramides of light, opposed at their bases, of which the axis was in the direction form North-West to South-East; the two points of light or the two summits are about 40 minutes of arc apart; I say about, because of the difficulty to recognize these two extreminties. The common base of the two pyramides is 15 minutes [of arc long]: these measures have been made with a Newtonian telescope of 4 feet & a half focal length, equipped with a micrometer of silk wires. With the same instrument I have compared the middle of the summits of the two cones of light with the star Gamma Andromedae of fourth magnitude which is very near to it, & little distant from its parallel. From these observations, I have concluded the right ascension of the middle of this nebula as 7d 26' 32", & its declination as 39d 9' 32" north. Since fifteen years during which I viewed & observed this nebula, I have not noticed any change in its appearances; having always perceived it in the same shape.
[p. 457] 1764.Aug. 3. RA: 7.26.32, Dec: 39. 9.32.B, Diam: 0.40. The beautiful nebula in the girdle of Andromeda.
[Also see Messier's memoir on the Andromeda Nebula M31 and its two companions, M32 and M110. Available online]
[1785. PT LXXV=75, p. 213-266; here p. 262]
The ninth [very compound Nebula, or Milky-Way] is that in the girdle of Andromeda, which is undoubtedly the nearest of all the great nebulae; its extent is above a degree and a half in length and, in even one of the narrowest places, not less than 16' in breadth. The brightest part of it approaches to the resolvable nebulosity, and begins to shew a faint red colour; which, from many observations on the colour of and magnitude of nebulae, I believe to be an indication that its distance in this coloured part does not exceed 2000 times the distance of Sirius. There is a very considerable, broad, pretty faint, small nebula [M110] near it; my Sister [Caroline] discovered it August 27, 1783, with a Newtonian 2-feet sweeper. It shews the same faint colour with the great one, and is, no doubt, in the neighborhood of it. It is not the 32d of the Connoissance des Temps [M32]; which is a pretty large round nebula, much condensed in the middle, and south following the great one; but this is about two-thirds of a degree north preceding it, in a line parallel to Beta and Nu Andromedae.
[1814. PT 1814 (vol. 104), p. 248-284; here p. 260]
8. Of objects of ambiguous construction
.. But when an object is of such a construction, or at such a distance from us, that the highest power of penetration, which hitherto has been applied to it, leaves it undetermined whether it belongs to the class of nebulae or of stars, it may be called ambiguous. As there is, however, a considerable difference in the ambiguity of such objects, I have arranged 71 of them into the following four collections. [First collection contains M31]
The first contains seven objects that may be supposed to consist of stars, but where the observations hitherto made, of either their appearance or form, leave it undecided into which class they should be placed.
Connoiss. 31 [M31] is "A large nucleus with very extensive nebulous branches, but the nucleus is very gradually joined to them. The stars which are scattered over it appear to be behind it, and seem to lose part of their lustre in the passage of their light through the nebulosity; there are not more of them scattered over the immediate neighborhood. I examined it in the meridian with a mirror of 24 inches in diameter, and saw it in high perfection; but its nature remains mysterious. Its light, instead of appearing resolvable with this aperture, seemed to be more milky."
The objects in this collection must at present remain ambiguous.
On NGC 206 (H V.36):
[1811: PT Vol. 1811, p. 226-336; here p. 280]
4. Of detached Nebulosities.
The nebulosities of the preceding article [on Nebulosities joined to Nebulae] are not restricted to an extensive diffusion; we meet with htem equally in detached collection; I shall only mention the following 6 [including H V.36 = NGC 206].
Last Modification: November 20. 2019