Discovered by Antoine Darquier de Pellepoix in January, 1779.
Discovered independently by Charles Messier on January 31, 1779.
- Messier:
M57.
- January 31, 1779. 57.
18h 45m 21s (281d 20' 08") +32d 46' 03"
"A cluster of light between Gamma & Beta Lyrae, discovered when looking
for the Comet of 1779, which has passed it very close: it seems that this
patch of light, which is round, must be composed of very small stars: with
the best telescopes it is impossible to distinguish them; there stays only
a suspicion that they are there. M. Messier reported this patch of light
on the Chart of the Comet of 1779.
M. Darquier, at Toulouse, discovered it when observing the same comet, and
he reports: "Nebula between gamma and beta Lyrae; it is very dull, but
perfectly outlined; it is as large as Jupiter & resembles a planet which
is fading"."
[From: Memoir on the Comet of 1779, Mem. Acad. for 1779, p. 318-372
+ Pl. XIV. Messier's discovery announce of M57, p. 320]
On January 31 [1779] in the morning. [..] When comparing in this morning the
Comet [C/1779 A1 Bode, Messier's 17th comet] with Beta in Lyra, I have
perceived with the refractor a small cluster of light, which has appeared to
me to be composed of very small Stars, which one could not distinguish with
the instrument: This rounded cluster of light was placed between Gamma &
Beta Lyrae. On September 3, I have once more examined that light with an
achromatic refractor, which I had made to magnify about 120 times; I could
not recognize, as for the first time, if it was composed of small Stars:
here is its position; I have also reported it on the Chart of the apparent
route of the Comet.
Nebula Right Northern
between Gamma and Beta Lyrae Ascension Declination
January 31, 1779 in the morning 281d 20' 8" 32d 46' 3"
[p. 352]
RA: 281.20. 8, Dec: 32.46. 3 N, No. 11.
In Lyra, discovered January 31, 1779.
- Darquier
- [Supplement zu Flamsteads Sternverzeichnis.. von Herrn Darquier zu Toulouse
(Supplement to Flamstead's star catalog .. by Mr. Darquier of Toulouse).
Astronomisches Jahrbuch für das Jahr 1784, p. 190-200, here p. 199]
RA 281d 20' 50" (18h 45m 19s), Dec 32d 45' 59" N, Nebula
This nebula, to my knowledge, has not yet been noticed by any astronomer.
One can only see it with a very good telescope, it is notresembling any of
those [nebula] already known; it has the apparent dimension of Jupiter, is
perfectly round and shrply limited; its dull glow resembles the dark part of
the Moon before the first and after the last quarter. Meanwhile, the center
appears a bit less pale than the remaining part of its surface.
- Bode [1781]
- [Supplement zu Flamsteads Sternverzeichnis.. von Herrn Darquier zu Toulouse
(Supplement to Flamstead's star catalog .. by Mr. Darquier of Toulouse).
Astronomisches Jahrbuch für das Jahr 1784, p. 190-200, here p. 199]
I have clearly seen this nebula between Beta and Gamma in Lyra, which was
not yet known to now, in the night between August 27 and 28 of this year
[1781] for the first time with a 3-foot [FL] Dollond telescope.
- William Herschel
-
[1785. PT LXXV=75 (1785), p. 213-66, here p. 263.
Reprinted in: Scientific Papers, Vol. I, p. 257]
A perforated Nebula, or Ring of Stars.
Among the curiosities of the heavens should be placed a nebula, that has a
regular, concentric, dark spot in the middle, and is probably a Ring of
stars. It is of an oval shape, the shorter axis being to the longer as about
83 to 100; so that, if the stars form a circle, its inclination to a line
drawn from the sun to the center of this nebula must be about 56 degrees.
The light is of the resolvable kind [i.e., mottled], and in the northern
side three very faint stars may be seen, as also one or two in the southern
part. The vertices of the longer axis seem less bright and not so well
defined as the rest. There are several small stars very bear, but none seems
to belong to it. It is the 57th of the Connoissance des Temps
[Messier's catalog]. Fig. 5 is a representation of it.
[PT 1814, p. 261, SP2 p. 527]
Connoiss. 57 [M 57 = NGC 6720] is "An oval nebula with an eccentric
oval dark space in the middle; there is a strong suspicion of its consisting
of stars. The diameter, measured by the large 10 feet, is 1'28".3."
[PT 1818, p. 445, SP2 p. 599]
The 57th of the Connoissance. [M 57 = NGC 6720]
"1782, 7 feet telescope. I suspect it to consist of very small stars; in the
middle it seems to be dark."
"1783, 1805, 1806, 10 feet telescope. With 130 it seems to be a rim of stars,
but with 350 there remains a doubt. It is a little oval; the dark place in
the middle is also oval; one side of the bright margin is a little narrower
than the other."
"1784, 1799, 20 feet telescope. It is an oval with a dark place within; the
light is resolvable. 240 showed several small stars near, but none that seems
to belong to it. It is near 2 minutes in diamter."
"1805, large 10 feet telescope. By a meridian passage of 7 seconds of
siderial time, the diameter is 1' 28".4."
By the observation with the 20 feet telescope, the profundity of the stars of
which it probably consists must be of higher than 900th order; perhaps 950.
- John Herschel (1833):
h 2023.
- h 2023 = M57.
Sweep 198 (August 1, 1829)
RA 18h 47m 13.2s, NPD 57d 10' 37" (1830.0)
[Right Ascension and North Polar Distance]
The annular nebula in Lyra. The diameter of the ellipse in R.A. = 6s.5::
It has a small star f exactly on the parallel of the centre, and distant from
the edge rather more than the breadth of the ring.
The annular nebula in Lyra. The diameter of the ellipse in R.A. is 6.5s ::
[unsure value]. It has a small star following [East of] exactly on the
parallel of the centre, and distant from the edge rather more than the
breadth of the ring.
Sweep 197 (July 31, 1829)
RA 18h 47m 13.4s, NPD 57d 11' 7" (1830.0)
Annular neb. between Beta and Gamma Lyrae. Pos of longer axis of annulus =
57deg.0 by microm. The small * f is almost exactly on the parallel of its
centre, dist about = breadth of the ring. The central vacuity is not
black; a nebulous light fills it. The edges are not sharply cut
off, very slightly ill defined. See fig. 29.
Annular nebula between Beta and Gamma Lyrae. Position angle of longer axis of
annulus is 57.0 deg by micrometer. The small [faint] star following is almost
exactly on the parallel of its centre, distance about the same as the breadth
of the ring. The central vacuity is not black; a nebulous light fills
it. The edges are not sharply cut off, very slightly ill defined.
See fig. 29.
Sweep 199 (August 5, 1829)
RA 18h 47m 17.6s ::, NPD 57d 11' 31" (1830.0)
R.A. not good, the sweeping zero having been interrupted by the disturbing
effect of the side motion in viewing object.
Sweep 168 (August 19, 1828)
NPD 57d 13' +/- (1830.0)
No RA, very rough PD; viewed; diameter in RA = 5s.375 by a mean of 4 careful
obs. The star following it = 11m. It follows the centre by 4s.31, and its pos
from the centre = 96deg.4 by microm. The neb has a mottled look. [N.B. The
mottled look, however, is something quite different from the appearance
called resolvable.]
No RA, very rough PD; viewed; diameter in RA is 5.375 s by a mean of 4 careful
observations. The star following it is of 11th magnitude. It follows the
centre by 4.31s, and its position angle from the centre is 96.4 deg by
micrometer. The nebula has a mottled look. [N.B. The mottled look, however,
is something quite different from the appearance called resolvable.]
[Appendix]
[Figure on Plate X, Figure 29, No. 2023, M. 57, RA 18h 47m 13s, NPD 57d 11']
Fig. 29. Mess. 57. - An annular nebula in Lyra. It is ill represented.
The edges exhibit a curdled and confused appearance, like stars out of focus.
The interior is far from absolutely dark. It is filled with a feeble but very
evident nebulous light, which I do not remember to have seen noticed by
former observers. Comparing figures 25 [M51], 27 [M64], 28 [H V.19, NGC 891],
29 and 48 [H 4. 13, NGC 6894], it will appear that the annular form, or an
approach to it, is one of those which nebulae affect, and taken in connexion
with the ring of Saturn or the Milky Way, may lead us to conceive some kind
of analogy, however obscure, may subsist in all those cases.
- Smyth:
DCLXIX [669]. M57.
- DCLXIX. 57 M. Lyrae.
AR 18h 47m 37s, Dec N 32d 50'.1
Mean Epoch of Observation: 1835.57 [Jul 1835]
[with drawing]
This annular nebula, between Beta and Gamma on the cross-piece of the Lyre,
forms the apex of a triangle which it makes with two stars of the 9th
magnitude; and its form is that of an elliptic ring, the major axis of which
trends sp to nf [SW to NE]. This wonderful object seems to have
been noted by Darquier, in 1779; but neither he nor his contemporaries,
Messier and Méchain, discerned its real form, seeing in this aureola
of glory only "a mass of light in the form of a planetary disc, very dingy in
colour." Sir W. Herschel called it a perforated resolvable nebula, and justly
ranked it among the curiosities of the heavens. He considered the vertices of
the longer axis less bright and not so well defined as the rest; and he
afterwards added, "By the observations of the 20-feet telescope, the
profundity of the stars, of which it probably consists, must be of a higher
than the 900th order, perhaps 950." This is a vast view of the ample and
inconceivable dimensions of the spaces of the Universe; and if the oft-cited
cannon-ball, flying with the uniform velocity of 500 miles an hour, would
require millions of years to reach Sirius, what an incomprehensible time it
would require to pass so overwhelming an interval as 950 times the distance!
And yet, could we arrive there, by all analogy, no boundary would meet the
eye, but thousands and ten thousands of other remote and crowded systems
would still bewilder the imagination.
In my refractor this nebula has a most singular appearance, the central
vacuity being black, so as to countenance the trite remark of its having a
hole through it. Under favourable circumstances, when the instrument obeys
the smooth motion of the equatoreal clock, it offers the curious phenomenon
of a solid ring of light in the profundity of space. The annexed sketch
affords a notion of it.
Sir John Herschel, however, with the superior light of his instrument, found
that the interior is far from absolutely dark. "It is filled," he says, "with
a feeble but very evident nebulous light, which I do not remember to have
been noticed by former observers." Since Sir John's observation, the powerful
telescope of Lord Rosse has been directed to this subject, and under powers
600, 800, and 1000, it displayed very evident symptoms of resolvability at
its minor axis. The fainter nebulous matter which fills it, was found to be
irregularly distributed, having several stripes or wisps in it, and the
regularity of the outline was broken by appendages branching into space, of
which prolongations the brightest was in the direction of the major axis.
- Lord Rosse
- [Phil. Trans. 1844, p. 321-324, drawing on plate XVIII, Fig. 29;
on his observation with his 3-feet (36-inch) aperture telescope]
The annular nebula in Lyra; 2 is the star in Sir John Herschel's sketch;
I have inserted the six other stars as in some degree tests of the power
of a telescope. Near star 3 there are two very minute stars seen with great
difficulty; the others are easily seen whenever the night is sufficiently
good to show the nebula well. The filaments proceeding from the edge become
more conspicuous under increasing magnifying power within certain limits,
which is strikingly characteristic of a cluster; still I do not feel
confident that it is resolvable. I am however disposed to think that it was
never examined when the instrument was in as good order , and the night as
favourable, as on several occasions when the resolvable character of
fig. 26 [M27] was ascertained.
[Actually neither of these nebulae is resolvable into stars -hf]
- Webb
- The only annular neb. accessible by common telescopes, fortunately easily
found, 1/3 of the distance from Beta towards Gamma [Lyrae]. It is somewhat
oval, and bears magnifying well. Its light I have often imagined fluctuating
and unsteady, like that of other plan. neb.; an illusion arising probably
from an aperture too small for the object.
- John Herschel, General Catalogue:
GC 4447.
- GC 4447 = h 2023 = M57; D'Arquier.
RA 18h 48m 20.1s, NPD 57d 8' 57.2" (1860.0)
[Right Ascension and North Polar Distance]
!!!; Annular Nebula; B; pL; cE (in Lyra).
14 observations by W. & J. Herschel.
Magnificient; annular shaped nebula; bright; pretty large; considerably
extended [elongated] (in Lyra).
Remark: Figures in:
P.T. 33 [J.H. 1833], plate ii, fig. 29;
P.T. 44 [Lord Rosse 1844], plate xix, fig. 29 (*);
D'Arr. [M. D'Arrest's Inaugural dissertation and description of the Copenhagen
Equatorial, 1861], plate ii, fig. 5.
(*) No. 4447, P.T. 44, xix, fig. 29. There is an error in this figure.
For Decl. 32 deg 49' n read 22deg 49' n.
- Huggins
- [On the Spectra of some of the Nebulae. Phil. Trans. Roy. Soc.,
Vol. 154 (1864), p. 437-444; here p. 440]
[No. 4447. 2023 h. 57 M. R.A. 18h 48m 20s. N.P.D. 57d 8' 57".2.
An annular nebula; bright; pretty large; considerably elongated.]
In Lyra (+).
The apparent brightness of this nebula, as seen in the telescope, is probably
due to its large extent, for the faintness of its spectrum indicates that it
has a smaller intrinsic brightness than the nebulae already examined. The
brightest of the three lines was well seen. I suspected also the presence of
the next in brightness. No indication whatever of a faint spectrum.
The bright line looks remarkable, since it consists of two bright dots
corresponding to sections of the ring, and between them was not darkness, but
an excessively faint line joining them. This observation makes it probable
that the faint nebulous matter occupying the central portion is similar in
constitution to that of the ring. The bright line was compared with the
induction-spark (++).
(+) Lord Rosse, in his description of this nebula, remarks, "The filaments
proceeding from the edge become more conspicuous under increasing magnifying
power within certain limits, which is strikingly characteristic of a cluster;
still I do not feel confident that it is resolvable."
- Philosophical Transactions, 1844, p. 322 and Plate XIX, fig. 29.
In 1850, Lord Rosse further remarks, "I have not yet sketched it with the
6-feet instrument, because I have never seen it under favourable
circumstances: the opportunities of observing it well on the meridian are
comparatively rare, owing to twilight. It was observed seven times in 1848,
and once in 1849. The only additional particulars I collect from the
observations are that the central opening has considerably more nebulosity,
and there is one pretty bright star in it, s. f. the centre, and a few other
very minute stars. In the sky round the nebula and near it there are several
very small stars which were not before seen; and therefore the stars in the
dark opening may possibly be merely accidental. In the annulus, especially
at the extremities of the minor axis, there are several minute stars, but
there was still much nebulosity not seen as distinct stars."
- Philosophical Transactions, 1850, p. 506.
"Nothing additional since 1844, except a star s. f. the middle."
- Philosophical Transactions, 1861, p. 732.
(++) Already in 1850 Lord Rosse had discovered a connexion in general plan of
structure between some of the nebulae which present small planetary disks in
ordinary telescopes, and the annular nebula in Lyra. His words are, "There
were but two annular nebulae known in the northern hemisphere when Sir John
Herschel's Catalogue was published; now there are seven, as we have found
that five of the planetary nebulae are really annular. Of these objects, the
annular nebula in Lyra is the one in which the form is the most easily
recognized." - Philosophical Transactions, 1850, p. 506.
[p. 442]
It is obvious that the nebulae 37 H IV (NGC 3242), Struve 6 (NGC 6572),
73 H IV (NGC 6826), 1 H IV (NGC 7009), 57 M, 18 H. IV (NGC 7662) and 27 M.
can no longer be regarded as aggregations of suns after the order to which
our own sun and the fixed stars belong. We have with these objects to do no
longer with a special modification only of our own type of suns, but find
ourselves in the presence of objects possessing a distinct and peculiar plan
of structure.
In place of an incandescent solid or liquid body transmitting light of all
refrangibilities through an atmosphere which intercepts by absorption a
certain number of them, such as our sun appears to be, we must probably
regard these objects, or at least their photo-surfaces, as enormous masses
of luminous gas or vapour. For it is alone from matter in the gaseous state
that light consisting of certain definite refrangibilities only, as is the
case with the light of these nebulae, is known to be emitted.
- D'Arrest
- [Siderum Nebulosorum Observationes Havnienses]
[Drawing on p. 334]
- Dreyer (1877)
-
GC 4447, h. 2023 [M 57].
Drawings in D'Arrest, S.N., p. 334,
and in Holden, Wash. Obs., 1874, Plate VI, Fig. 2.
Vol. VIII of the Annals of the Observatory of Harvard College, which was
received at Birr Castle in the summer 1877, contains lithographs from
drawings by Mr. Touvelot of the following Nebulae:
GC 116 [M 31] (Pl. 33), 1179 [M 42] (Pl. 24, Woodbury type),
4230 [M 13] and 4294 [M92] (Pl. 25), 4355 [M20] (Pl. 32),
4447 [M57] (Pl. 34), 4532 [M27] (Pl. 35).
- Dreyer:
NGC 6720.
- NGC 6720 = GC 4447 = h 2023; M 57, Darquier.
RA 18h 48m 23s, NPD 57d 8.6' (1860.0)
[Right Ascension and North Polar Distance]
!!!, ring, B, pL, cE (in Lyra); = M57
Magnificient, ring shaped, bright, pretty large, considerably extended
[elongated] (in Lyra).
Remark: Figures in:
P.T. 33 [J.H. 1833], plate ii, fig. 29;
P.T. 44 [Lord Rosse 1844], plate xix, fig. 29 (*);
d'A [d'Arrest, Instrumentum magnum aequatoreum, Havniae, 1861],
plate ii, fig. 5;
d'A 2 [d'Arrest, Siderum Nebulosorum Observationes Havnienses, 1867],
p. 334;
Wash. [Holden and Trouvelot, Washington Observations, 1874, App. I],
plate VI, fig. 2;
H.C. [Winlock and Trouvelot, Annals of Harvard Observatory,
vol. viii], plate 34.
- Curtis
- [Descriptions of 762 Nebulae ans Clusters photographed with the Crossley
Reflector. Publ. Lick Obs., No. 13, Part I, p. 9-42]
NGC 6720, RA=18:49.9, Dec=+32:54.
[Publ. Lick Obs.] Vol. VIII, Plate 59. M57; the well-known Ring Nebula in
Lyra. Planetary. See the sketch included in the paper on Planetary
Nebulae [description below]. 5 s.n.
[The Planetary Nebulae. Publ. Lick Obs., No. 13, Part III, p. 55-74]
[with drawing and Lick b/w photo, Fig. 46 and 46a]
NGC 6720; 18h 49.9m; +32d 54'
The Ring Nebula in Lyra. Exposures 1m to 2h. Central star magn. 15.5
visual (Burnham) and about 13 photographically. The outside dimensions are
about 83"x59" in p.a. 66deg. The structural details of this well known and
remarkably complex object are accentuated in the drawing [Fig. 46].
Rel. Exp. 6.