Discovered by Philippe Loys de Cheseaux in 1745-46.
Independently rediscovered by Charles Messier on June 3, 1764
[Mem. Acad. for 1771, p. 442-443 (first Messier catalog)]
In the same night [June 3 to 4, 1764], I have discovered at little distance of the cluster of stars of which I just have told, a train of light of five or six minutes of arc in extension, in the shape of a spindle, & in almost the same [shape] as that in the girdle of Andromeda [M31]; but of a very faint light, not containing any star; one can see two of them nearby which are telescopic & placed parallel to the Equator: in a good sky one perceives very well that nebula with an ordinary [non-achromatic] refractor of 3 feet & a half [FL]. I have determined its position in right ascension of 271d 45' 48", & its declination of 16d 14' 44" south.
[p. 456] 1764.Jun.3. RA: 271.45.48, Dec: 16.14.44.A, Diam: 0. 5. Train of light without stars, little distant from the preceding star cluster.
[Unpublished Observations of Messier's Nebulae and Clusters.
Scientific Papers, Vol. 2, p. 652]
1783, July 31. A very singular nebula; it seems to be the link to join the nebula in Orion to others, for this is not without a possibility of being stars. I think a great deal more of light and a much higher power would be of service.
1784, June 22 (Sw. 231). A wonderful nebula. Very much extended, with a hook on the preceding [Western] side; the nebulosity of the milky kind; several stars visible in it, but they seem to have no connection with the nebula, which is far more distant. I saw it only through short intervals of flying clouds and haziness; but the extent of the light including the hook is above 10'. I suspect besides, that on the following [Eastern] side it goes on much farther and diffuses itself towards the north and south. It is not of equal brightness throughout and has one or more places where the milky nebulosity seems to degenerate into the resolvable [mottled] kind; such a one is that just following the hook towards the north. Should this be confirmed on a very fine night, it would bring on the step between these two nebulosities which is at present wanting, and would lead us to surmise that this nebula is a stupendous stratum of immensely distant fixed stars, some of whose branches come near enough to us to be visible as a resolvable nebulosity, while the rest runs on to so great a distance as only to appear under the milky form.
Sweep 274 (July 27, 1830)
RA 18h 10m 46.8s, NPD 106d 14' 5" (1830.0)
The small insulated, resolvable knot in the preceding, strait branch of the nebula.
Sweep 358 (July 30, 1831)
RA 18h 10m 51.8s, NPD 106d 14' 19" (1830.0)
The same knot. See description of this neb in the Appendix. See also figure.
Sweep 33 (July 24, 1826)
NPD 106d 15' 48":: (1830.0)
A most curious object, not unlike the nebula in Orion (as it used to be figured, like a Greek capital Omega.) There is in it a resolvable portion or knot distinctly separated from and insulated in the rest as if it had absorbed the nebula near it. (A figure carefully drawn.) (The P.D. inaccurate, being much past merid.)
Sweep 48 (August 6, 1823)
NPD 106d 15' 27":: (1830.0)
A large extended nebula. Its form is that of a Greek Omega with the left (or following) base-line turned upwards. The curved (or horse-shoe) part is very F, and has many stars in it. The preceding base-line hardly visible. The following, which is the principle branch, occupies nearly half the field (7 1/2'.) Its light is not equable, but blotty. Strong twilight.
[Figure on Plate XII, Figure 35, No. 2008, M. 17, RA 18h 10m 45s, NPD 106d 15']
Fig. 35. Mess. 17. - The figure of this nebula is nearly that of the Greek capital Omega, somewhat distorted and very unequally bright. It is remarkable that this is the form usually attributed to the great nebula in Orion, though in that nebula I confess I can discern no resemblence whatever to the Greek letter. Messier perceived only the bright preceding branch of the nebula now in question, without any of the attached convolutions which were first noticed by my Father. The chief peculiarities which I have observed in it are, 1st, the resolvable knot in the following portion of the bright branch, which is in a considerable degree insulated from the surrounding nebula; strongly suggesting the idea of an absorption of nebulous matter; and 2ndly, the much feebler and smaller knot in the north preceding end of the same branch, where the nebula makes a sudden bend at an acute angle. With a view to a more exact representation of this curious nebula, I have at different times taken micrometrical measures of the relative places of the stars in and near it, by which, when laid down on the chart, its limits may be traced and identified, as I hope soon to have better opportunity to do than its low situation in this latitudes will permit.
Last Modification: February 20, 2005