What is a black hole and how are they made? Can life actually exist around black holes and could these cosmic enigmas be gateways to parallel universes? Find out the answer to these questions and more...
We may not be able to see them, but black holes are out there. There’s even one at the centre of the Milky Way. But what is a black hole? And how are they made? These questions and more are answered in this new title from the makers of All About Space. Uncover the truth behind the creation of black holes, and get up close with the primordial giants that have been around since just after the Big Bang. Find out what happens when black holes turn white, and take a trip to the Event Horizon Telescope to see how the first-ever picture of a black hole was taken. We also take a look at questions that have plagued astrophysicists for decades. Can life actually exist around black holes? Can…
“As stars age, the fuel eventually starts to run out” 1 Many black holes started life as stars Stars spend their entire lifetimes resisting gravitational collapse. Their enormous mass means that the gas is continually pulled towards the core, but instead of collapsing down, atoms collide and fuse, releasing explosive atomic energy. Radiation pushes outwards against gravity, holding the star open as a glowing ball of gas. As stars age, more of the atoms are fused, creating heavier elements, and eventually the fuel starts to run out. Without the outwards push, the balance is tipped in favour of gravity, and the star begins to collapse. For small stars, such as the Sun, the collapse is incomplete, and repelling forces manage to hold the last glowing embers open as a white…
Explaining Black Holes The science of black holes Black holes are the most mysterious objects in the universe. They are a place where physics is pushed to its most extreme, where even light cannot escape and where, space-time itself is twisted and even punctured, leading to the most incredible and counter-intuitive phenomena. If we were to describe a black hole in a single sentence, it would say that a black hole is a region of space where gravity is so strong that nothing hot even light - can escape from its grasp. Within a certain proximity of one, any closer than the black hole’s so-called ‘event horizon’, you’d have to travel faster than light to get away from it. Since, as far as scientists know, nothing can go faster than light,…
1 Birth of a massive star Forming from the collapse of a cloud of gas and dust, some stars are born bigger, brighter and hotter than others, glowing a bright blue. 2 Beginning of the end Massive stars use up their hydrogen fuel more quickly, after just a few million years, and when they can no longer maintain nuclear fusion in their core they begin to swell up, becoming a red supergiant. 3 The stellar core implodes When fusion reactions stop, the force of gravity causes the core to implode to form a compact neutron star. The surrounding layers of the star rebound off the neutron star core, exploding as a supernova. 4 Gravitational collapse If the star - or more specifically its core - is massive enough, the neutron star will…
Cygnus X-1 Location: 6,070 light years away Mass: 21.2 Suns A stellar-mass black hole orbiting a blue supergiant star. The black hole is stealing gas from the star, forming an accretion disc which occasionally outbursts in X-rays. Sagittarius A* Location: 26,000 light years away Mass: 4.1 million Suns The supermassive black hole at the centre of our Milky Way galaxy. It is generally inactive, with only modest X-ray outbursts as it consumes small gas clouds. Messier 87’s black hole Location: 54 million light years away Mass: 6.5 billion Suns The first black hole to be imaged right down to the event horizon by the Event Horizon Telescope, which saw the black hole’s ‘shadow’ on the surrounding accretion disc. GW 150914 Location: 1.4 billion light years away Mass: 62 Suns The…
Relativistic jet Powerful magnetic fields weaving through the accretion disc can funnel charged particles away from the black hole in beams or jets that emanate from above and below the black hole’s rotational axis. Static limit The edge of the ergosphere. Everything inside the static limit is caught up by the mass of the black hole, dragging the fabric of spacetime with it as it rotates. Ergosphere An oblate zone around a rotating black hole, the ergosphere is a volume of space from where energy and mass can be extracted from the black hole. Singularity The core of a black hole is a mysterious point of mass called a singularity, where our current laws of physics break down. Event horizon The point of no return, where the gravity from the…
