Black holes come in a wide variety of forms, from small stellar-mass bodies to the supermassive beasts that reside at the hearts of galaxies. Here are 10 of the most extreme black holes, from the smallest to the largest and from cannibals to rogues.
FIRST UP: The biggest and baddest
One of these galaxies, known as NGC 3842 — the brightest galaxy in the Leo cluster nearly 320 million light years away — has a central black hole containing 9.7 billion solar masses. The other, NGC 4889, the brightest galaxy in the Coma cluster more than 335 million light years away, has a black hole of comparable or larger mass.
The gravitational range, or "event horizon," of these black holes is about five times the distance from the sun to Pluto. For comparison, these black holes are 2,500 times as massive as the black hole at the center of the Milky Way galaxy, whose event horizon is one-fifth the orbit of Mercury.
NEXT UP: The smallest
NEXT UP: Cannibal black holes
The discovery is the first of its kind. Astronomers had witnessed the final stages of the merging of galaxies of equal mass — so-called major mergers — but minor mergers between galaxies and smaller companions had long eluded researchers.
Using NASA's Chandra X-ray Observatory, investigators detected two black holes at the center of a galaxy dubbed NGC3393, with one black hole about 30 million times the mass of the sun and the other at least 1 million times the mass of the sun, separated from each other by only about 490 light-years.
NEXT UP: Spitting gas bullets
NEXT UP: The oldest black hole
The ancient age of this black hole actually poses some problems for astronomers. This brilliant enigma appears to be 2 billion times the mass of the sun. How black holes became so massive so soon after the Big Bang is difficult to explain.
NEXT UP: Bright black holes
As supermassive black holes at the centers of galaxies suck in surrounding gas and dust, they can spew out huge amounts of energy. The brightest quasar we see in the visible range is 3C 273, which lies about 3 billion light-years away.
NEXT UP: Rogue black holes
NEXT UP: Mid-size monsters
However, middle-weight black holes had eluded astronomers for years. Scientists recently discovered an intermediate-mass black hole, called HLX-1 (Hyper-Luminous X-ray source 1), approximately 290 million light-years from Earth, which appears to be about 20,000 solar masses in size.
Medium-size black holes are thought to be the building blocks of supermassive black holes, so understanding more about them can shed light on how these monsters and the galaxies that surround them evolved.
NEXT UP: Super-fast spinners
An item placed on the edge of the black hole's event horizon — the edge past which nothing can escape — would spin around it at a speed of more than 333 million mph (536 million kph), or about half the speed of light.
NEXT UP: Tabletop black holes
For instance, black holes possess gravitational pulls so powerful that nothing, including light, can escape after falling past a border known as the event horizon. Scientists have created an artificial event horizon in the lab using fiber optics. They have also recreated the so-called Hawking radiation thought to escape from black holes.