Department of History
University of California, Irvine
Instructor: Dr. Barbara J. Becker
Week 3. The Three Chief World Systems.
His Astronomicall Coniectur of the
New and Much Admired [Star] which Appered in the Year 1572 (1632)
by Tycho Brahe
[translated from the Latin into English by V.V.S.]
Tycho points to the New Star; his motto, Non Haberi Sed Esse (To be present, but not seen) appears above his instruments.
Translated according to his Originall Astronomicall Prediction.
That which I intended to deliver to posterity, concerning the New and admirable Starre which appeared in the yeare 1572 in the beginning of November, and near unto the Constellation of Cassiopea, I have now finished, and by Gods assistance (from whom wee acknowledge all things to bee received) brought it to a desired end. And I thinke that in those things which I have propounded and explained, no materiall point is omitted, having taken such paines in finding out the truth, and clearing it from the pollutions of error, that all those who understand the Mathematickes, and will consider of things with a sincere judgment, shall find no occasion eyther to doubt or contradict.
But yet to the end that those things which I proposed to divulge concerning this strange and wonderfull Starre, being written according to the Rules of Astronomy, and compared with other mens opinions, might attaine to the greater perfection; I thought it meet in the former part of this Booke, to intreat of some things in generall, thereby to lay a ground-worke, not onely to the Explanation of this Starre, but also to the whole Science of Astronomy....
I have described no lesse than eight hundred of the fixed Starres, and have assigned them their several places, according to their Longitude and Latitude.... [A]nd have added to these all the other chief Starres, which doe appear neare the Zodiacke: and so at last we discended to the rectification of the Starres belonging to the Constellation of Cassiopea, the knowledge whereof, we knew would availe much to our present purpose. And now albeit, the performance hereof in due manner required more study and labour, then the unexperienced can judge, who are ready to alledge that I have tooke more paines in searching out and declaring the nature of this Starre according to the fundamentall Rules of Astronomie, then indeed was necessary. Yet to the end, that some solid and certaine truth might bee knowne concerning this unusuall appearance, I thought fit to lay a sound and firme foundation to build upon, which could not be performed without the rectification of the course of the Sunne, and the fixed Starres....
But if I seeme to have heaped divers matters together, in more ample manner, than the proper attributes of this Starre did require, I have done it to that end, that so I might profit the whole Art of Astronomy, and might vindicate it from divers faults as occasion was offered; for which I hope I shall rather deserve thankes, than the envie of those which are studious of this Sublime Science. And moreover this Starre, of which I purposed chiefly to intreat, albeit it were ascitious [an addition] and chanceable; yet because it shined forth most miraculously, and contrary to the Lawes of Nature, even in the highest Firmament, like to the other Naturall Starres, and stood there fixed and immoveable for the space of a whole yeare and more, it seemed fit that some diligent paines should be taken, in considering andunfolding the circumstances belonging thereunto....
For albeit, it shined without a taile or any scattered beames, (for then it had beene a Comet) yet neverthelesse it might be likened to some of those appearances, which are beheld in the forme of obscure starres without any streaming beard at all, and so doe exercise some proper motion, as that did which was seene in the yeare 1585. But howsoever, it doth not repent us of our labour which we have bestowed, according as our time and leysure would permit us; inasmuch as we trust that those things which we have delivered will be much availeable, not onely to point out the due place and position of this novell Starre, but also of all the other starres in the firmament, and likewise for the exact measuring of the course of the Planets. For if our Ancestors had used that diligence which they ought to have done, in decyphering the motions of the Sunne, and in rectifying the true places of the fixed starres according to their Longitude and Latitude, we might then have spared that labour ... and might presently have declared those things which concerned the Starre it selfe, whose description we had undertaken....
[Concerning] Paralax, I have cleerely prooved by divers invincible reasons that it had none at all, and that it was exalted, not onely above the Elementary Region, and the confines of the Moone, but farre beyond the Orbes of the Planets, even to the highest Spheare of the fixed starres, and so at last I have measured his true magnitude, and that I might the more truly compare it both to the Earth, and to the Celestial bodies, I have also prescribed the orders, and quantities of the Planets, and fixed starres, according as they are placed in the Heavens, though somewhat different from my Predecessors in the same kinde.
One of Tycho's explanations for the new star's varying brightness: like a planet, it resides on a moving sphere (RP) that carries it nearer (M) and farther (O) from the earth (A).
Lastly ... I have compared the opinions of other men concerning this matter, and have examined them by the Touchstone of truth.... I have weighed their opinions who have eyther come neere unto the truth, or wandred from it concerning this new Starre, which I have done, that so the truth might appeare and shine forth, more clearely, and not by flattery to obtaine the favour of any one, by reciting their opinions who have judged somewhat neare the matter, nor yet to enveigh against those who have produced strange conceits very wide from the purpose; but I have onely tooke care, that the truth might not be violated in any thing, but have endeavoured to suppresse their boasting endeavours, who eyther through ignorance, or wilfulnesse have opposed themselves against it, and have openly rejected and confuted their erronious opinions. For so the truth shall bee more easily brought to light, not onely by inducing probable conceits, but also by removing contrary and erronious supponsions.
But when I consider with my selfe, how many vaine opinions there have beene concerning this Starre, both in respect of his scituation and distance from the Earth (when yet they were more easie to be found out, in regard of the immobilitie of the Starre, and in that it appeared alwayes above the Horizon, than in Commets which are alotted some motion) I doe not so much wonder at it, seeing not onely the motions of the Starres are not hitherto declared in such an accurate manner as is fitting; but also, that there doe so many questions and controversies arise in Philosophy and Divinity.
For if that which plainely appeared to the sight and might easily be measured and demonstrated Geometrically by fit Instruments, was yet subject to so great variety of difference of Judgements: how much more those things which are not discernable by the senses, nor subject to humaine industry, but are so full of doubts and perplexities, that truth (which is alwayes but one as the center in the Circle) is very hardly or never found out. Hence arises so great a confusion of opinions in every Science, and divers severall questions are discussed, not onely in naturall Philosophy, but also in Divine and Morall Matters, that it is hard to find out, and firmely to establish any certainty, which may bee equall to Geometricall demonstrations, or which cannot bee contradicted. Such are the blind apprehension of mans nature, and in such a darknesse of error doe we spend our dayes heere on Earth. And therefore moved by these considerations, I have illustrated and discovered whatsoever I thought did belong to the consideration of the unusuall Starre, both by declaring the true nature thereof, as also by detecting the errours of divers and sundry Writers:
Now there remaineth yet two other questions to bee unfolded, whereof the one is Physicall, concerning the matter and procreation of this Starre; the other Astrologicall, concerning the effects and signification thereof, whereof I purposed not to intreat seriously, or by way of judiciall divination to set downe any certainty in this present Worke, in as much as they are not subject to the senses nor to any geometricall demonstration, but are onely grounded upon probable conjectures, and not on Mathematicall Principles: Yet neverthelesse, because many doe desire a Physicall and Prognosticall explanation of this Starre, and are very desirous to see them set forth, especially, the latter, therefore for the satisfaction of their minds, I will declare my opinion concerning this Starre, but yet with this caution, that those things which I shall disclose are not to be compared in respect of their indubitable certainty, with that which I have propounded demonstratively in the former part of my Booke; for these Prognostick matters are grounded onely upon conjecturall probabilitie....
Therefore, concerning the matter of this adventitious Starre, that I may first give you my opinion at thinke it was Coelestiall, not differing from the matter of the other Starres, but yet in this it did admit of some diversitie, that it was not exalted to such a perfection, nor solid composition of the parts, as appeareth in the everlasting and continuing Starres: and therefore it had no perpetuall duration, as these have, but was subject in processe of time to dissolution; forasmuch as this Starre could not consist of any elementary matter, sith that cannot be carried into the highest part of the ayre, nor can obtaine there any firme place of abiding. Besides, this Starre did at the first in his magnitude exceed the whole Globe of the Earth, and was three hundred times bigger then the whole circumference thereof, and therefore what sublunary matter could be sufficient to the conformation of it.
But some may say, how or whence could it bee framed of Coelestiall matter; I answere that the Heavens did afford it themselves, in like manner as the Earth the Sea, and the Ayre; if at any time they exhibite some strange sight, doe produce it out of their owne proper substance. For although the Heaven it selfe be thinne and pervious, giving way to the motion of the Starres without any hinderance, yet it is not altogether incorproeall, for then it should be infinite and without place. Therefore the very matter of Heaven, though it be subtile, and possible to the courses of the Planets, yet being compacted and condensated into one Globe, and being illustrated by the light of the Sunne, might give forme and fashion to this Starre. Which because it had not his beginning from the common order of nature, therefore it could not have a continuall duration equall to the rest; as in like manner, new and monstrous generations arising and compounded out of the Elements cannot long endure.
And albeit the large vastnesse of the Coelestiall world may afford sufficient matter for the conformation of any adventitious Starre, yet there is no where more plenty then neere unto Via lactea or the Milkie way, which I suppose to be a certaine heavenly substance not differing from the matter of the other Starres, but diffus'd and spread abroad, yet not distinctly conglobated in one body, as the Starres are and hence I conjecture it came to passe, that this Starre appeared in the edge of the milkie way, and had the same substance as the Galaxia hath.
Besides, there is discerned a certain marke or scarre as it were in that part of the Galaxia, wherein this Starre was seated, as in a cleare night when the milkie way is not vailed with cloudes we may easily perceive. Which marke or scarre I never saw before this Starre did arise, neither did I ever reade of it. But howsoever, the substance of the milkie Zone is able to supply matter for the framing of this Starre, which because it had not attained so excellent a consummation, and solid existence, as the genuine and naturall Starres have, therefore it was subject to dissolution and dissipation, eyther by its owne nature, or by the multiplicitie of the beames of the Sunne and other Starres.
Neither is Aristotle here to be allowed of, who disapproving of the opinions of others, doth himselfe bring in no lesse absurdities, while hee maketh the Galaxia to be a certain sublunary concretion attracted and formed out of the Starres which are above it; so that it becommeth a Meteor, in the highest part of the Ayre, not unlike to the Comets, which he (grounding one absurdity upon another) supposeth to be generated there. For if it were so, the Milkie way would not have continued in the same form, place, and Magnitude, as it hath done from the beginning of the world.
And besides, other Starres would attaine unto the like Luminous concretion; And moreover, this Galaxia of Aristotle, would then admit of a Paralax, and according to the opticke consideration, by the shining of the fixed Starres through it, it would beget a strange refraction, differing from that which is occasion'd by the vapors that are seene about the Horizon,which seldome riseth to the twentieth degree of Altitude, when this proceeding from the Via lactea would reach to the greatest height. All which, Aristotle rather guessed at, grounding it upon conjecture rather than on the doctrine of the Mathematicks & opticks, and therefore it is no marvell, if he hath endeavoured, to banish those seldome appearing Comets out of the heaven, and to equall them to sublunary Meteors, whereby he hath thrust downe the Galaxia beneath the Moone, and hath made it participant of a sublunary nature. Hence it is, that Aristotle and other Philosophers, have joyned the description and explication of the Galaxia, together with the Commets, because they knew not, the affinity which is betweene, having onely learned by experience, or by the relation of ancient writers, that these beamy Starrs have their originall and beginning neere to the Milkie way.
Neither can it be a Solæcisme [an impropriety], in that I affirme, that this new Starre was framed of Coelestiall matter, being the same whereof the Galaxia and other Starres doe consist, yet not so well compacted; when we may discerne the like productions in the Earth, which bringeth forth mettals and precious stones. Yet though all mettals and jems have one and the same matter, yet all are not concocted and brought to the same subtility and maturity by the powerfull working of nature; hence it is, that some are sooner corrupted, others very hardly; so that pure gold and silver, in respect of the homogemly and perfection of their parts, are able to resist the violence of the fire, without any losse or detriment at all, when more imperfect mettals, as Lead and Tinne, are soone calcinated into ashes, or else vanish into smoake; In like manner, this Starre might bee framed of Coelestiall matter, although it had not attained to such a perfect existence as the naturall Starres; and therefore, it could not with them be able to endure the beames of the Sunne and Starres, and the motion of the Heaven, and withall it was subject to a successive alteration, untill at last it was quite dissolv'd. But why this Starre although it had the same matter with the Galaxia, which is not obnoxious to corruption, yet was in time extinct, I wil declare some reasons hereafter....
[I]f there were ever any difficulty in discerning, and foretelling the significations of the Starres, truly this new Starre,which appeared in our age for a whole yeare together, doth require much labour and diligence, in revealing the Portent thereof, and in shewing what it might signifie....
[A]s this was a rare and wonderfull Starre, shining forth in the heavens unexpectedly, so it is likely and probable, that it will produce strange, great, and wonderfull effects, but what they shall be in particular, I thinke no mortall man is able to guesse, being as farre distant from our knowledge, as the rising of this Starre was before it did appeare......