The establishment of the festival was initiated by President VÃ¡clav Havel, who opened Prague Castle to artists at the beginning of the 1990s in order to attract the public. The first performance of Shakespeare took place here in 1990 and the festival has been held here regularly since 1998.
1 A black dwarf is a white dwarf that has cooled sufficiently such that it no longer emits any visible light. 2  A brown dwarf is a substellar object not massive enough to ever fuse hydrogen into helium, but still massive enough to fuse deuterium âless than about 0.08 solar masses and more than about 13 Jupiter masses.
A white dwarf is very dense: its mass is comparable to that of the Sun, and its volume is comparable to that of Earth. A white dwarf's faint luminosity comes from the emission of stored thermal energy. The nearest known white dwarf is Sirius B, at 8.6 light years, the smaller component of the Sirius binary star.There are currently thought to be eight white dwarfs among the hundred star systems nearest the Sun. The unusual faintness of white dwarfs was first recognized in 1910.sually, therefore, white dwarfs are composed of carbon and oxygen. If the mass of the progenitor is between 8 and 10.5 solar masses (Mâ), the core temperature is sufficient to fuse carbon but not neon, in which case an oxygen-neonâ magnesium white dwarf may be formed.