Supernova 1572, one of the three observed and documented supernovae that erupted in our Galaxy in the distant past. It was named after the Danish astronomer Tycho de Brahe, who observed its explosion on November 11, 1572, and the course of its brightness until it disappeared from the sky (it was also observed by Tadeáš Hájek z Hájku). At that time, he did not know that the star had exploded at a distance of 8,000 light-years. The star shone in close proximity to the northwest of the star κ Cas. At its peak, it reached an apparent magnitude equal to Venus, reaching a maximum brightness of -4.0 mag and was visible even during the day. Then its brightness decreased, but it could still be seen with the naked eye for a period of 16 months. Today, it is once again a star with an apparent brightness of less than 19 mag, with an expanding nebula, a radio and X-ray source of radiation.