The question of the star's distance from the earth being one of special interest, all observers tried to determine the daily parallax, but the results varied immensely according to the skill of the observer. While several writers, in addition to those already mentioned, state that they could find no perceptible parallax,[1] others found a large one. Thus Elias Camerarius at Frankfurt on the Oder had at first thought that he had found a parallax of 12′, but in January 1573 he could only find one of 412′, from which he concluded that the star had in the meantime receded from us in a straight line (so that its apparent place was not altered), and that this was the cause of its diminished brightness. A German writer of the name of Nolthius tried to find the parallax by a method suggested by Regiomontanus from the hour angle, the azimuth and the latitude of the observing station, comparing the altitude computed from these with the observed one. He chose, however, a bad time for the experiment, when the altitude was very great (77°), and it is not to be wondered at that he found an absurd result—39′ for the parallax—and it does not seem to have struck him that this would correspond to a parallax equal to 2° 42′ at the lowest altitude of the star, which could not have escaped even casual observers, as pointed out by Tycho.[2]
Of greater interest than these crude attempts are the statements of the various writers as to the time when the star first became visible. Some writers say that the star was already seen early in October, but none of them are entitled to much credit. The above-named Elias Camerarius at Frankfurt on the Oder says that it appeared "in principio Octobris Anni 1572 uesperi circa horam 10 prope Meridi-
- ↑ Thus Paul Fabricius at Vienna, Hainzel (using the great quadrant at Augsburg), Reisacher at Vienna, Corn. Gemma (not stating how found), Hieronimus Munosius at Valencia, Valesius from Covarruvias (physician to Philip II. of Spain), and Johan Prætorius (Richter), professor at Wittenberg.
- ↑ Progymn., i. p. 760.
