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[M 45]

Messier 45

Observations and Descriptions

Known pre-historically. Mentioned by Homer about 750 B.C. and by Hesiod about 700 B.C.

Messier: M45.
March 4, 1769. 45. 3h 33m 48s (53d 27' 04") +23d 22' 41"
A cluster of stars, known by the name of the Pleiades. The position reported is that of the star Alcyone.

[Mem. Acad. for 1771, p. 451-452 (first Messier catalog)]
One can say the same [as for M44] for the Pleiades, by reporting their position by that of the star Eta, with its right ascension becoming, for March 4, 1769, 53d 27' 4", & its declination 23d 22' 41" north.
[p. 458] 1769.Mar. 4. RA: 53.27. 4, Dec: 23.22.41.B. Cluster of stars known by the name Pleiades: the position reported is that of the star Alcyone.

[Messier reports to have measured the stars of the Pleiades in 1785, 1790, and 1796.]

Hodierna: Ha. I.1
[1654] [1.] The first, and the most lumious of all assemblies of stars, shines in the belly of Taurus; six, or seven stars are most evident, before many others, .. [counted 37 stars]

Bode: Bode 8.
A wellknown cluster of small stars.
[Position of Alcyone in the Pleiades in Taurus]

Bode (1782):
[From: Vorstellung der Gestirne auf XXXIV Kupfertafeln (Introduction to the Stars on 34 Copper Plates), 1782.]
[Ch. 14, p. 17] No. 15 to 28 are the stars of the Pleiades.
[p. 18] The Pleiades are represented on the 14th plate at the right, by the 28 stars of Flamsteed, T. Mayer & le Monnier. On the 1st figure of the 30th plate, there are also the stars from 203 to 242, with diverse others which have been observed by the Abbé Outhier; these are those which I have increased the Pleiades to a number of 120 stars.

[Plate XXX, p. 38]
Fig. 1. The Seven Sisters or the Pleiades in the Bull, consisting of about 120 stars, which have been observed in them by Flamsteed, le Monnier, T. Mayer and the Abbot Outhier, and are visible through telescopes. The most considerable of them are annoted with letters according to Flamsteed. After the fables of the poets the Pleiades were the seven daughters of Atlas and of Pleione, and from these [fables], nine stars of them have got the following names from this family, namely:

    g. Celano.   c. Maia.   f. Atlas.
    b. Electra.   d. Merope.   h. Pleione.
    e. Taygeta.   Eta. Alcyone.   k. & l. Asterope 1. and 2.

Smyth: CXLII (142). Eta Tauri.
[Smyth has separate entries for 4 individual stars in the Pleiades, but describes the cluster under the star Eta Tauri. The four separate entries are CXXXVIII. 19 Pleiadum (Taygeta), CXXXIX. 15 Pleiadum (of mag 8), CXL. 23 Pleiadum (Merope), and CXLIV. 27 Pleiadum (Atlas)]
CXLII. Eta Tauri.
AR 3h 37m 59s, Dec N 23d 36'.3
Mean Epoch of Observation: 1836.97 [Dec 1836]
Alcyone, a Greenwich star, with a distant companion, in the midst of the Pleiades, called by the Arabians Jauza, the wall-nut, and Neyyir, bright, or lucida [the brightest] of the Pleiades. A 3 [mag], greenish yellow; B 7, pale white. Piazzi marked this "duplex," but the comes could only be 151 P. III.; and a reduction from his mean apparent places, and the micrometrical measures of Sir John South, afford these results:
    P.  Pos. 288d 00'  Dist. 122".50  Ep. 1800
    S.       288d 42'        116".40      1824
which, considering that A is chargeable with a small proper motion both in AR abd declination, is very consistent with more recent observations. The other two small stars in the same, or np [north preceding, NW] quadrant, form the "binae ad boream" mentioned in 150 P. III; and were also measured by S. The proper motions alluded to, are thus valued:
    P. .... AR -0".04   Dec -0".09
    S. ....    +0".06       -0".05
This star has usually been considered as the one described under the 32nd of Taurus, in Ptolemy, and there marked Epsilon in brightness. But Mr. Baily says, "I don't think this star can be Eta Tauri, on account of its magnitude: yet it is singular that the brightest star in the pleiades should not have been noticed by Ptolemy (*)."

The occultation of this star, and h Pleiadum, by the dark limb of the Moon, were well observed on the 19th March, 1839, by my [Smyth's] excellent friend Lord Chief Justice Tindal; who thus elegantly occupied the evening of a tedious assize-day at Bedford. The observations were made with the 8 1/2-foot equatorial, charged with an eye-piece magnifying ninety-three times.

The Pleiades constitute a celebrated group of stars, or miniature constellation, on the shoulders of Taurus; their popular influences have been said and sung for many years. Hesiod mentions them as the Seven Virgins, "of Atlas born;" and in the ancient M.S. of Cicero's Aratus, in the British Museum, they are finely represented by female heads, inscribed Merope, Alcyone, Celaeno, Electra, Taygeta, Asterope, and Maia, under the general title Atlantides, - while the illustrations to Julius Firmicius in 1497, represents them as well-grown women. The moral may be, that Atlas himself first rigidly observed these stars, and named them after his daughters.But various are the appellations under which they have been known. THeon liked them to a bunch of grapes; Aratos says they were called Eptaporoi; Manilius clusters them as glomerabile sidus; the Arabs said they were Ath-thurayya, or the little ones; the French designate them as poussinière; the Germans, gluckhenne, the Italians knew them as le gallinelle; the Spaniards term them the cabrillas, or little manny-goats, which is the key of the Duke's query to sancho; and several schools called them brood-hen, under the representation of a hen with chickens. There has also been much discussion as to the number of the individuals in the group, some of the ancients having advanced that there were seven, and others resolving to count six, in the spirit of Ovid's oft-cited
Quae septem dici, sex tamen esse solent.
The "lost Pleiad" is however, rather a poetical than an exact expression, for in moonless nights I never had any difficulty in counting seven stars in the so-called Hexastron, with the naked eye; and indeed this is nothing to boast of, for many people may enumerate even more, though few will equal with Maestlinus, the discoverer of the new star of 1604, who, as Kepler avers, could distinctly see fourteen stars in the Pleiades, without any glasses. Still, if we admit the influence of variability at long periods, the seven in number may have occasionally been more distinct; so that while Homer and Attalus speak of six of them, Hipparchus and Aratus may properly mention seven. But they have a singular brilliant light for their magnitudes, whence the unassisted eye becomes dazzled. The ancients allotted to them only seven stars; but in modern catalogues, their numbers have run thus:
    Kepler   . . . . 32 stars     Hook   . . . . .  78 stars
    Galileo  . . . . 36           Jeaurat  . . . . 103
    De la Hire . . . 64           F. de Rheita . . 188
And the zealous amateur may be assured, that there are yet many recruits for him who will undertake an exact chart of them, the which is still a desideratum, the cluster being directly in the Moon's path, and therefore the site of abundance of occultations. This part formerly constituted the Third Lunar Mansion; and is so generally known, that is, alineation need hardly be pointed out; yet it may be added, that an imaginary line through the wain of the Great Bear, passing Capella, leads to the Pleiades; or, from the southwest, a line from Sirius, carried over Orion's belt, meets them.

John Herschel, General Catalogue:
The Pleiades are not in the GC catalog, however, the first discovered nebula around Merope is:

The Pleiades are not in the NGC or IC catalog, however some of the nebulosities within them are:

Pleiades ... RA 03:41. , Dec +23:48 (1900.), Diam 120'; class D3 [Coarse, irregular, stars of different magnitudes (cluster)], B1 [Large, diffused, irregular (nebula)]
! Cluster, well known cluster of bright stars, not given in the N.G.C.
Remarks: Pleiades. The number of stars which really belong to this cluster is doubtful. Several thousand stars have been photographed in this region, but there is no proof that many of these belong to the cluster, since even this large number is no greater, if, indeed, it is as great, as that in an equal area of the surrounding regions. Apparently the cluster itself consists of a few bright stars.
Plate I, Figure 1. The Pleiades. The original photograph shows faintly and brighter nebulosities, but a much longer exposure is needed with the Bruce telescope to show them to good advantage. See Mem. Acad. Amer. Acad. 11, 224. The area shown in this, and in each of the following three figures is a triffle more than two square degrees.

[Descriptions of 762 Nebulae ans Clusters photographed with the Crossley Reflector. Publ. Lick Obs., No. 13, Part I, p. 9-42]
...., RA= 3:41 , Dec=+24:.. The Pleiades. L.O. Publ., Vol. VIII, Plate 8. 0 s.n.
  • Observing Reports for M45 (IAAC Netastrocatalog)

    Hartmut Frommert
    Christine Kronberg

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    Last Modification: February 5, 2005