Black Star

Black Star or Blackstar may refer to:

In astronomy

In astrology

In entertainment

Black star (semiclassical gravity)

A black star is a gravitational object composed of matter. It is a theoretical alternative to the black hole concept from general relativity. The theoretical construct was created through the use of semiclassical gravity theory. A similar structure should also exist for the Einstein-Maxwell-Dirac equations system, which is the (super)classical limit of quantum electrodynamics, and for the Einstein-Yang-Mills-Dirac system, which is the (super)classical limit of the standard model.

A black star need not have an event horizon, and may or may not be a transitional phase between a collapsing star and a singularity. A black star is created when matter compresses at a rate significantly less than the freefall velocity of a hypothetical particle falling to the center of its star, because quantum processes create vacuum polarization, which creates a form of degeneracy pressure, preventing spacetime (and the particles held within it) from occupying the same space at the same time. This vacuum energy is theoretically unlimited, and if built up quickly enough, will stop gravitational collapse from creating a singularity. This may entail an ever-decreasing rate of collapse, leading to an infinite collapse time, or asymptotically approaching a radius less than zero.

Black Star (Babylon 5)

Black Star (Drala Fi' in Minbari) was a Sharlin Class Warcruiser in the fictional science fiction universe of Babylon 5. The Black Star served as one of the flagships of the Minbari Federation fleet, until its destruction in the year 2245. (Some sources give a different class name for the Black Star, referring to it as a "Shargotti" class. This is chiefly because the Black Star was shown to be larger than other Sharlins which it traveled with, and thus may have been a different class. The class of the Black Star has never been stated on screen.)

As told in the episode Points of Departure, during the course of the Earth-Minbari war, on September 30, 2245 the Black Star entered the asteroid belt between Jupiter and Mars. There the Earth Alliance warship Lexington was escorting a number of warships and supply vessels. The far more advanced and powerful Black Star proceeded to quickly destroy and disperse most of the Earth fleet. The Lexington was heavily damaged and crippled in the attack. The ship's commanding officer, Captain Roger Stearns, was killed in the attack when a large metal beam was ripped off the bridge's ceiling and hit him. Commander John Sheridan, the ship's first officer, survived the attack and took command of the Lexington. Knowing that it was only a matter of time before the Black Star found the Lexington, Sheridan devised a strategy that would use the asteroid belt to his advantage. He ordered the belt mined with nuclear weapons, and then transmitted a fake distress signal to lure the ship toward the Lexington. Sheridan knew that it was standard Minbari doctrine to ignore all surrender pleas and destroy all Earth vessels without mercy, regardless of any damage the Earth vessels may have sustained. As the Black Star approached his ship for the kill, Sheridan detonated the nuclear mines attached to nearby asteroids, catching the Minbari ship in the explosions and destroying it.