Page:Cyclopaedia, Chambers - Volume 2.djvu/778

 S T A

[ 122 ]

S T A

were reduced into 48 Confteliations, and he laid it down, that if there fometimes appeared more in Winter Nights, 'twas owing to a Deception of the Scnfe.

Wtokaty added Four Stars to Hipparchus's Catalogue, and made the Number 1026.

In the Year 1437, Uleig Seigh, Grandfon of Tamerlane, in a New Catalogue he made, only gives 1017.

But in the 17th Century, when Aftronomy began to be retrieved, their Number was found to be much greater.

To the 48 Confteliations of the Ancients, were added 12 New ones, discovered towards the South Pole, and two to- wards the North : Befides feveral others not universally ad- mitted, as the Flower- deLys, the Royal Oak, Zyc.

lycho Srahe publifhed a Catalogue of 777 Stars, from his own Observations 5 which Kepler, from Ototomy and others, increafed to 1163, Ricciokls to 1468, and Bayer to 1725 : Dr. Halley added 373 obferv'd by him, within the Antarctic Circle. Hevelkis, "from his own Observations, and thofe of Dr. Halley, made a Catalogue of 18SS Stars : And Mr. Flamfiead has Since made a Catalogue of no lefs than 3000 Stars, all from his own moll accurate Obfervations. See Catalogue.

Of thefe 3000, 'tis true, there are many only vifible through a TeleScope ; nor does a good Eye fcarce ever fee more than an Hundred together in the cleareft Heaven : The Appearance of innumerable more, frequent in clear winter Nights, arifes from our Sight's being deceived by their Twinkling, and from our viewing them confufedly, and not reducing them to any Order.

Yet for all this, the Stars are really almofl infinite, Riccioli, makes no Scruple to affirm, in his new Mmagejl, That a Man who Should fay there arc above Twenty thoufand times Twenty thoufand, would fay nothing improbable.

For a good TeleScope di reeled almoft to any Point of the Heavens, discovers Numbers that are loft to the naked Sight 5 particularly in the Milky Way, which is nothing but an AStemblage of Stars, too remote to be Singly feen, but fo ciofeiy difpofed, as to give a luminous Appearance to that Part of the Heavens where they are. See Galaxy.

In the Single Conftellation of the 'Pleiades? inftcad of 6 or 7 Stars feen by the beft Eye, Dr. Hook, with a TeleScope 12 Foot long, told 78 5 and with larger GlaSTes, many more of different Magnitudes. F.deRbeita, a Capuchin, affirms, That he has observed above 2000 Stars in the Single Conftella- tion of Orion. ,

The fame Author found above 188 in the Pleiades. And Huygens looking at the Star in the Middle of Orion's Sword ; inftead of one, found it to be 12. Gallilcri found 80 in Orion's Sword ; 21 in the Nebulous Star of his Head 5 and 36 in the Nebulous Star, c Pr<efepe.

Changes in the Stars.

The Changes that have happened in the Stars, are very considerable : contrary to the Opinion of the Ancients, who held, that the Heavens and heavenly Bodies, were incapable of any Change, the Matter thereof being Permanent and Eternal, infinitely exceeding the HardneSs of Diamonds, and not fufceptible of any different Form. And, in EfEecl, till the Time of Arifiotle, and even 200 Years afterwards, there had no Change been obferved.

The firff, was in the Year 125", before the Incarnation ; when Hipparchus discovering a new Star to appear, was firft induced to make a Catalogue of the Stars, that Pofterity, as we have obferved, might perceive any future Changes of the like Kind.

In the Year 1572, 'lycho Srahe, obferved another new Star in the Conftellation Caffiopozia, which was, likewife, the Occasion of his making a new Catalogue. Its Magnitude, at firff, exceeded that of the biggeft of our Stars, Sirius and Lyra ; it even equalled that of Venus, when neareft the Earth ; and was feen in fair Day-light. It continued Sixteen Months ; towards the latter Part whereof, it began to dwindle, and at laft totally difappeared, without any Change of Place in all that Time.

Leovicius tells us of another Star appearing in the fame Conftellation, about the Year 90^, which refembled that of 15725 and quotes another ancient Obfervation, whereby it appears, that a new Star was feen about the fame Place in 1264.

Dr. Keill takes thofe to have been all the fame Star ; and does not know but it may make its Appearance a-new j 50 Years hence.

Fabricius difcovercd another new Star in the Neck of the Whale, which appeared and difappeared feveral times in the "Years 1648 and 1662. Its Courfe and Motion, are defcribed by M. Souilland.

Simon Marius difcovercd another in Andromedafs Girdle ; in 16 12 and 1613, though M. Souilland fays, it had been feen before, in the XVth Century. Another was obferved by Kepler in Serpentarius. Another of the Third Magnitude in .the Conftellation CygfiUS, near the Bill, in the Year 1601, which difappeared in 1626, and was obferved again by

He-velius in 1659, till the Year 1561, and again in r*/r j 1671, ?s a Star of the Sixth Magnitude. 66 and

'Tis certain, from the ancient Catalogues, that many of tf, ancient Stars are now invifible. This i's particularly notorio in the Pleiades, or Seven Stars, whereof only Six are now vifible to the Eye 5 a Thing long ago obferved hy OviT Witnefs the Verfe, g>na Sephmdici, fix tamen ejfe fllent

M. Montanere, in his Letter to the Royal Society i n jg.. obferves, that there are now wanting in the Heavens, two Stars of the fecond Magnitude, in the Stern of the* Shin JJrgo and its Yard ; which had been feen till the Year J664. When they firSt disappeared 'tis not known 5 but he aflurcs us, there was not the leafl Glimpfe of them in iggg He adds, he has obferved many more Changes in the f tX 'i Stars, even to the Number of an Hundred.

Nature of the fix' 'd Stars.

For the Nature of the fix'd Stars, their immenfe Diftance leaves us greatly at a lofs about it. What we can gather for certain from their Phenomena, is as follows ;

i oc That the fix' d Stars are greater than cur Earth. This is demonstrable thus : SuppoSe two Stars C and D (Tab. Aftronomy Fig. 31.) the one in the Eaftern Horizon, and the other in the Weftern. As foon as D arrives in Cf C will appear in D. But Since both move with the fame Velocity, while C defcribes the Arch CHD ; the Star C defcribing an equal Arch CDH, will appear inF: Wherefore, if the Stars C and D be lefs than the Earth, the Star C will not be feen in the Eaftern Horizon, when the other, C, is arrived at the Weftern : But as this is contrary to Experience, it follows, that the Stars being in L and S, and there feen at the fame time by Spectators iiy A and B, are greater than the Earth AB.

2 The fix'd Stars are farther difiantfrom the Earth, than thefarthefi of the Planets. For we frequently find the fx'i Stars, hid behind Saturn's Body 5 the higheft of the Planets. See Occultat-ion.

3 <the fix' 'd Stars Jbine with their own Light : For they are much further from the Sun than Saturn, and appear much JeSs than Saturn ■ but fince, notwithstanding this, they are found to Shine much brighter than Saturn, 'tis evident they cannot borrow their Light from the fame Source as Saturn does, viz, the Sun : But fincc we know of no other luminous Body befide the Sun, whence they might derive their Light ; it follows, that they Shine with their own native Light.

Hence 1% we deduce, that the fix'd Stars are fo many Suns 5 for they have all the Characters of Suns. See Sun.

2° That in all probability, the Stars are not lefs than our Sun.

3° That 'tis highly probable, each Star is the Centre of a SyStem, and has Planets or Earths revolving round it, in the fame Manner as round our Sun; i, e. has opake Bodies illuminated, warirfd and cheriSh'd by its Light. See System.

How immenfe, then, does the Uni verfe appear ! Indeed, it muff either be Infinite, or infinitely near it. See Universe.

Kepler, 'tis true, denies that each Star can have its Syftem of Planets as ours has 5 and takes them all to be fix'd in the fame Surface or Sphere ■ urging, that were there one twice or thrice as remote as the other, it would appear twice or thrice as fmall, fuppofing their real Magnitudes equal ; whereas there is no Difference in their apparent Magnitudes, juftly obferved, at all. But to this we oppofe, that HuygenS has not only Shewn, that Fires and Flames are feen at fuch Distances, where other Bodies, comprehended under equal Angles, dis- appear $ but it Should likewife feem, that the Optic Theorem about the apparent Diameters of Objects being reciprocally proportional to their Diftances from the Eye, does only hold while the Diameter of the Objeft has fome fenfible Ratio & its Diftance.

4° 'The Stars which appear and difappear by turns, being always found to increafe in Magnitude at their firft Appearance, and to decreaSe as they begin to difappear, and being like- wife ftill vifible through TeleScopes, for fbme Time after they are loft to the naked Eye ("of which we have various Inftances in the Philofophkal Iran] "actions) feem to be no other tbittt Planets performing their Periods about the fix'd Stars, as their refpeffive Suns 5 unlefs anyPerSbn fliould rather incline to Dr. KeilVs Opinion, viz. That the Stars lofe their Bright- nefs, and difappear, bv their becoming cover 'd with Macule or Spots, fuch as are frequently found to over-fpread the Sun. See Spots,

5 Thofe temporary Stars, which, upon their disappearing* have never been found to return again 5 arc probably conjectured to be of the Number of Comets, which make long Excursions from their Suns, or the Centers of the upper planetary Syftcms, i. e. from the fix'd Stars ; returning too Seldom to have their Returns perceived. See Comet.

Motions of the Stars.

The fix'd Starshzvc two kinds of Motions ; one called the Frrft, common or diurnal Motion, or the Motion of the Tr?'