The more massive a black hole, the colder it is. Stellar black holes are very cold: they have a temperature of nearly absolute zero – which is zero Kelvin, or −273.15 degrees Celsius.
Astronomers have discovered a jet of X-rays coming out of the heart of a black hole which is 60,000 times hotter than the sun's surface.
Black holes are freezing cold on the inside, but incredibly hot just outside. The internal temperature of a black hole with the mass of our Sun is around one-millionth of a degree above absolute zero.
"The most massive black holes in the Universe, the supermassive black holes with millions of times the math [sic] of the Sun will have a temperature of 1.4 x 10−14 Kelvin. That's low. Almost absolute zero, but not quite. A solar mass black hole might have a temperature of only 0.00000006 Kelvin."
Because of the fuzziness of quantum particles, energy cannot be completely bound by a black hole's event horizon. Sometimes energy can escape its gravitational prison through a process known as Hawking radiation. The amount of energy that escapes is tiny, but it means that black holes have a (very cold) temperature.
Stellar black holes are very cold: they have a temperature of nearly absolute zero – which is zero Kelvin, or −273.15 degrees Celsius. Supermassive black holes are even colder. But a black hole's event horizon is incredibly hot. The gas being pulled rapidly into a black hole can reach millions of degrees.
According to the National Aeronautics and Space Administration, the coldest point in the cosmos is the Boomerang Nebula. According to NASA, the Boomerang Nebula is the coldest spot in the known cosmos, with a temperature of one degree Kelvin.
The hottest thing in the Universe (Supernova)
Supernovas are the hottest thing in the Universe as they reach a million degrees Celsius. These explosive events occur when a star between 8 and 40 times more massive than our Sun reaches the end of its stellar lifecycle and explodes when its core collapses.
But don't expect a black hole to disappear any time soon. It takes a shockingly long time for a black hole to shed all of its mass as energy via Hawking radiation. It would take 10100 years, or a googol, for a supermassive black hole to fully disappear.
Astronomers have discovered the closest black hole to Earth, the first unambiguous detection of a dormant stellar-mass black hole in the Milky Way. Its close proximity to Earth, a mere 1,600 light-years away, offers an intriguing target of study to advance understanding of the evolution of binary systems.
Black holes are dark, dense regions in space where the pull of gravity is so strong that nothing can escape. Not even light can get out of these regions.
Some black holes, called supermassive black holes, may have as much matter as 1000 million Suns! The more matter something has, and the closer an object is to that matter, the stronger the gravity.
Although the odds of Earth getting swallowed by a black hole, or any Solar System planet, for that matter, are low, it's definitely a real possibility.
General relativity says that when matter falls into a black hole, information is destroyed, but quantum mechanics says firmly it can't be. A unified theory requires us to somehow reconcile the two, probably by reimagining space-time as only an approximate thing.
The temperature in a supernova can reach 1,000,000,000 degrees Celsius. This high temperature can lead to the production of new elements which may appear in the new nebula that results after the supernova explosion.
A CERN experiment at the Large Hadron Collider created the highest recorded temperature ever when it reached 9.9 trillion degrees Fahrenheit.
Is it possible for a black hole to "eat" an entire galaxy? No. There is no way a black hole would eat an entire galaxy. The gravitational reach of supermassive black holes contained in the middle of galaxies is large, but not nearly large enough for eating the whole galaxy.
Don't let the name fool you: a black hole is anything but empty space. Rather, it is a great amount of matter packed into a very small area - think of a star ten times more massive than the Sun squeezed into a sphere approximately the diameter of New York City.
Contrary to popular belief, the Solar System would not be sucked in: a solar-mass black hole would exert no more gravitational pull than our Sun. As this computer simulation shows, the planets would actually continue on in their orbits as if nothing had happened. Are you a journalist?
Physicists acknowledge they can never reach the coldest conceivable temperature, known as absolute zero and long ago calculated to be minus 459.67°F.
Taking the Moon's Temperature
Daytime temperatures near the lunar equator reach a boiling 250 degrees Fahrenheit (120° C, 400 K), while nighttime temperatures get to a chilly -208 degrees Fahrenheit (-130° C, 140 K). The Moon's poles are even colder.
Even at its very end, no matter how far into the future we go, the Universe will always continue to produce radiation, ensuring that it will never reach absolute zero.