Tycho Brahe was a Danish astronomer, known for his accurate and comprehensive astronomical observations. Born in Scania, which became part of Sweden in the next century, Tycho was well known in his lifetime as an astronomer, astrologer, and alchemist.

  His precise measurements indicated that “new stars” (stellae  novae, now called  supernovae) in particular that of 1572 (SN 1572), lacked the parallax expected in sublunar phenomena and were therefore not tail-less comets in the atmosphere, as previously believed, but were above the atmosphere and beyond the Moon. Using similar measurements, he showed that comets were also not atmospheric phenomena, as previously thought, and must pass through the supposedly immutable celestial spheres.

   Tycho’s Nova, also called B Cassiopeiae or SN 1572, one of the few recorded supernovas in the Milky Way Galaxy. The Danish astronomer Tycho Brahe first observed the “new star” on Nov. 11, 1572. Other European observers claimed to have noticed it as early as the preceding August, but Tycho’s precise measurements showed that it was not some relatively nearby phenomenon, such as a comet, but at the distance of the stars, and that therefore real changes could occur among them