Stellar-mass black holes are born when the most massive stars in the Cosmos collapse in the raging, brilliant fireworks of a supernova explosion. The supernova marks the end of the very massive star's life as a main-sequence (hydrogen-burning) star. After such a hole has been born, it can continue to gain weight by devouring its surroundings. Black sun journal In March 2013, astronomers studying a weird black hole system, announced that they had spotted a disk of matter circling the entire system. Such a structure has never been seen before, and it is believed that this mysterious disk is the hideous tattle-tale result of the black hole devouring its doomed binary-star sister and victim!

In the 18th century, John Michell and Pierre-Simon Laplace predicted the existence of black holes, which are gravitational monstrosities. Albert Einstein's Theory of General Relativity also went on to describe the presence of bizarre objects with such deep gravitational wells that anything luckless enough to wander too close to its maw would be devoured. However, the real existence of such objects seemed so far-fetched that Einstein himself rejected the concept.

In 1916, Karl Schwarzschild calculated the first modern solution of General Relativity that could describe a black hole--although its interpretation as a region of Space from which nothing--not even light--could escape was not fully grasped for almost half-a-century. Such bizarre and fascinating objects were dismissively viewed as mere mathematical oddities for decades. It was not until the 1960s that theoretical calculations showed that black holes are a generic prediction of Einstein's General Relativity.

Only the most massive stars in the Universe collapse to form black holes. A star is a gigantic ball of searing-hot, incandescent gas that is pulled in very tightly by the force of gravity. This makes the hidden heart of a star extremely dense, as well as fiery-hot. Stars are so hot that they catch fire in a process termed nuclear fusion, whereby atoms of lighter elements meld together to spin increasingly heavier and heavier elements (stellar nucleosynthesis). The fundamental fusion process begins with atoms of hydrogen. Hydrogen is the most abundant, as well as the lightest, atomic element in the Universe--and the stars fuse hydrogen in their hot, hidden hearts to form the next-lightest-of-all- atomic elements--helium.

Nuclear fusion liberates energy. This is the reason why stars shine with their brilliant glittering fire. The energy that is released exerts an outward pressure on the glowing, very hot star. This pressure creates a delicate balance, with gravity pulling in, as radiation pressure pushes out! This delicate balance between pressure and gravity continues for as long as the star "lives". The precise balance between pressure and gravity is determined by the mass of the star. The most massive stars are squeezed most tightly. This process speeds up the nuclear reactions, which churns out more and more radiation. When a star finally burns up its nuclear fuel, gravity wins the war over pressure. The mass of the star determines just how great the victory of gravity will be over its opponent.