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.
No longer emitting heat or light, the white dwarf will become a black dwarf, its loss making it difficult to find. However, the black dwarf would still retain its mass, allowing scientists to detect the effects produced by its gravitational field. But there's no need to start searching for the elusive black dwarfs yet. At the moment, they are strictly theoretical. Scientists have calculated that a white dwarf will take tens of hundreds of billions of years to cool down and become a black dwarf.