therefore, at first have been much more than a hundred times as large as the earth, but it has decreased in size. It twinkles like other stars, while the planets do not twinkle, which is another proof of its belonging to the eighth sphere. Having mentioned the change in colour, he finishes the astronomical part of the treatise on the star by remarking that the change in colour and magnitude does not prove it to be a comet or a similar phenomenon, for if it is possible that a new body can be generated in the æthereal region, as he has proved to be the case in opposition to the opinions of all philosophers, it must be considered far less impossible and absurd that this new star should change in brightness and colour. And if it could ever, beyond the ordinary laws of nature, have been seen in the heavens, it would not be more absurd if it should again cease altogether to be visible, though again in opposition to those laws.
Tycho now proceeds to give his opinion about the astrological effects of the new star.[1] These cannot be estimated by the usual methods, because the appearance of the star is a most unusual phenomenon. The only known precedent is the star said to have appeared at the time of Hipparchus, about B.C. 125. It was followed by great commotions both among the Jewish people and among the Gentiles, and there is no doubt that similar fatal times may be expected now, particularly as the star in Cassiopea appeared nearly at the conclusion of a complete period of all the Trigoni.[2] For in about ten years the watery Trigon will
- ↑ Fol. D. 2 verso to E. 3.
- ↑ As some readers may not be familiar with the phraseology of astrology, it may be well to mention here that each Trigonus consists of three signs of the Ecliptic, 120° from each other; the four Trigoni correspond to the four elements, and each of them is in turn the ruling one, until a conjunction of planets has taken place within one of its signs. In about 800 years the four Trigoni will all have had their turn, and a cycle is completed. See, e.g.,
