Tycho Brahe days list. One should also note that Denmark was on the Julian calendar until 1700, when it switched to the Gregorian calendar. Medieval calendars often contained lists of "dies Ægyptiaci", "Egyptian days", that also were held to be unlucky. The Egyptian days were: These too were days considered unlucky to begin any enterprise. Physicians were especially discouraged from performing bloodletting on the Egyptian days. Tycho Brahe days In the folklore of Scandinavia, Tycho Brahe days (Danish: "Tycho Brahes-dage"; Norwegian: "Tycho Brahedager"; Swedish: "Tycho Brahe-dagar") are days judged to be especially unlucky, especially for magical work, and important business transactions[ and personal
Tycho Brahe parallax over any period of six months, during which the angular orientation of a given star would change thanks to Earth's changing position. (This parallax does exist, but is so small it was not detected until 1838, when Friedrich Bessel discovered a parallax of 0.314 arcseconds of the star 61 Cygni.) The Copernican explanation for this lack of parallax was that the stars were such a great distance from Earth that Earth's orbit was almost insignificant by comparison. However, Tycho noted that this explanation introduced another problem: Stars as seen by the naked eye appear small, but of some size,