Supermassive Black Holes - Blog Posts
Rare & Record-Breaking Black Holes
While even the most “normal” black hole seems exotic compared to the tranquil objects in our solar system, there are some record-breaking oddballs. Tag along as we look at the biggest, closest, farthest, and even “spinniest” black holes discovered in the universe … that we know of right now!
Located 700 million light-years away in the galaxy Holmberg 15A, astronomers found a black hole that is a whopping 40 billion times the mass of the Sun — setting the record for the biggest black hole found so far. On the other hand, the smallest known black hole isn’t quite so easy to pinpoint. There are several black holes with masses around five times that of our Sun. There’s even one candidate with just two and a half times the Sun’s mass, but scientists aren’t sure whether it’s the smallest known black hole or actually the heaviest known neutron star!
You may need to take a seat for this one. The black hole GRS 1915+105 will make you dizzier than an afternoon at an amusement park, as it spins over 1,000 times per second! Maybe even more bizarre than how fast this black hole is spinning is what it means for a black hole to spin at all! What we're actually measuring is how strongly the black hole drags the space-time right outside its event horizon — the point where nothing can escape. Yikes!
If you’re from Earth, the closest black hole that we know of right now, Mon X-1 in the constellation Monoceros, is about 3,000 light-years away. But never fear — that’s still really far away! The farthest known black hole is J0313-1806. The light from its surroundings took a whopping 13 billion years to get to us! And with the universe constantly expanding, that distance continues to grow.
So, we know about large (supermassive, hundreds of thousands to billions of times the Sun's mass) and small (stellar-mass, five to dozens of times the Sun's mass) black holes, but what about other sizes? Though rare, astronomers have found a couple that seem to fit in between and call them intermediate-mass black holes. As for tiny ones, primordial black holes, there is a possibility that they were around when the universe got its start — but there’s not enough evidence so far to prove that they exist!
One thing that’s on astronomers’ wishlist is to see two supermassive black holes crashing into one another. Unfortunately, that event hasn’t been detected — yet! It could be only a matter of time before one reveals itself.
Though these are the records now, in early 2021 … records are meant to be broken, so who knows what we’ll find next!
Add some of these records and rare finds to your black hole-watch list, grab your handy-dandy black hole field guide to learn even more about them — and get to searching!
Keep up with NASA Universe on Facebook and Twitter where we post regularly about black holes.
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Cosmic Couples and Devastating Breakups
Relationships can be complicated — especially if you’re a pair of stars. Sometimes you start a downward spiral you just can’t get out of, eventually crash together and set off an explosion that can be seen 130 million light-years away.
For Valentine’s Day, we’re exploring the bonds between some of the universe’s peculiar pairs … as well as a few of their cataclysmic endings.
Stellar Couples
When you look at a star in the night sky, you may really be viewing two or more stars dancing around each other. Scientists estimate three or four out of every five Sun-like stars in the Milky Way have at least one partner. Take our old north star Thuban, for example. It’s a binary, or two-star, system in the constellation Draco.
Alpha Centauri, our nearest stellar neighbor, is actually a stellar triangle. Two Sun-like stars, Rigil Kentaurus and Toliman, form a pair (called Alpha Centauri AB) that orbit each other about every 80 years. Proxima Centauri is a remote red dwarf star caught in their gravitational pull even though it sits way far away from them (like over 300 times the distance between the Sun and Neptune).
Credit: ESO/Digitized Sky Survey 2/Davide De Martin/Mahdi Zamani
Sometimes, though, a stellar couple ends its relationship in a way that’s really disastrous for one of them. A black widow binary, for example, contains a low-mass star, called a brown dwarf, and a rapidly spinning, superdense stellar corpse called a pulsar. The pulsar generates intense radiation and particle winds that blow away the material of the other star over millions to billions of years.
Black Hole Beaus
In romance novels, an air of mystery is essential for any love interest, and black holes are some of the most mysterious phenomena in the universe. They also have very dramatic relationships with other objects around them!
Scientists have observed two types of black holes. Supermassive black holes are hundreds of thousands to billions of times our Sun’s mass. One of these monsters, called Sagittarius A* (the “*” is pronounced “star”), sits at the center of our own Milky Way. In a sense, our galaxy and its black hole are childhood sweethearts — they’ve been together for over 13 billion years! All the Milky-Way-size galaxies we’ve seen so far, including our neighbor Andromeda (pictured below), have supermassive black holes at their center!
These black-hole-galaxy power couples sometimes collide with other, similar pairs — kind of like a disastrous double date! We’ve never seen one of these events happen before, but scientists are starting to model them to get an idea of what the resulting fireworks might look like.
One of the most dramatic and fleeting relationships a supermassive black hole can have is with a star that strays too close. The black hole’s gravitational pull on the unfortunate star causes it to bulge on one side and break apart into a stream of gas, which is called a tidal disruption event.
The other type of black hole you often hear about is stellar-mass black holes, which are five to tens of times the Sun’s mass. Scientists think these are formed when a massive star goes supernova. If there are two massive stars in a binary, they can leave behind a pair of black holes that are tied together by their gravity. These new black holes spiral closer and closer until they crash together and create a larger black hole. The National Science Foundation’s LIGO project has detected many of these collisions through ripples in space-time called gravitational waves.
Credit: LIGO/T. Pyle
Here’s hoping your Valentine’s Day is more like a peacefully spiraling stellar binary and less like a tidal disruption! Learn how to have a safe relationship of your own with black holes here.
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How does time work in a black hole?
Is there such thing as a ‘gentle black hole’ (as in Interstellar) that would one day be a candidate for sending probes? Or is it a lost cause?
Could you theoretically time travel through a black hole or other object with such intense mass?
How do blackholes form and how do they move ?
I love astrophysics and especially black holes and I want to pursue a career on them, but to be honest I'm scared to be not good enough or not clever enough. How did you decide to work on black holes? How did you become the person you are today?
Got a question about black holes? Let’s get to the bottom of these odd phenomena. Ask our black hole expert anything!
Black holes are mystifying yet terrifying cosmic phenomena. Unfortunately, people have a lot of ideas about them that are more science fiction than science. Don’t worry! Our black hole expert, Jeremy Schnittman, will be answering your your questions in an Answer Time session on Wednesday, October 2 from 3pm - 4 pm ET here on NASA’s Tumblr! Make sure to ask your question now by visiting http://nasa.tumblr.com/ask!
Jeremy joined the Astrophysics Science Division at our Goddard Space Flight Center in 2010 following postdoctoral fellowships at the University of Maryland and Johns Hopkins University. His research interests include theoretical and computational modeling of black hole accretion flows, X-ray polarimetry, black hole binaries, gravitational wave sources, gravitational microlensing, dark matter annihilation, planetary dynamics, resonance dynamics and exoplanet atmospheres. He has been described as a "general-purpose astrophysics theorist," which he regards as quite a compliment.
Fun Fact: The computer code Jeremy used to make the black hole animations we featured last week is called "Pandurata," after a species of black orchid from Sumatra. The name pays homage to the laser fusion lab at the University of Rochester where Jeremy worked as a high school student and wrote his first computer code, "Buttercup." All the simulation codes at the lab are named after flowers.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Five Reasons You Wouldn’t Want to Live Near a Black Hole
Black holes are mystifying yet terrifying cosmic phenomena. Unfortunately, people have a lot of ideas about them that are more science fiction than science. Black holes are not cosmic vacuum cleaners, sucking up anything and everything nearby. But there are a few ways Hollywood has vastly underestimated how absolutely horrid black holes really are.
Black holes are superdense objects with a gravitational pull so strong that not even light can escape them. Scientists have overwhelming evidence for two types of black holes, stellar and supermassive, and see hints of an in-between size that’s more elusive. A black hole’s type depends on its mass (a stellar black hole is five to 30 times the mass of the Sun, while a supermassive black hole is 100,000 to billions of times the mass of the Sun), and can determine where we’re most likely to find them and how they formed.
Let's focus on supermassive black holes for now, shall we? Supermassive black holes exist in the centers of most large galaxies. Some examples are Sagittarius A* (that’s pronounced “A-star”) at the center of our Milky Way and the black hole at the center of galaxy Messier 87, which became famous earlier this year when the Event Horizon Telescope released an image of it. As the name suggests, these black holes are — well — supermassive. Why are they so enormous? Scientists suspect it has something to do with their locations in the centers of galaxies. With so many stars and lots of gas there, they can grow large rapidly (astronomically speaking).
You may have seen a portrayal of planets around supermassive black holes in the movies. But what would the conditions on those worlds actually look like? What kinds of problems might you face?
1. 100% chance for cosmic winds
“Space weather” describes the changing conditions in space caused by stellar activity. Solar eruptions produce intense radiation and clouds of charged particles that sweep through our planetary system and can affect technology we rely on, damaging satellites and even causing electrical blackouts. Thankfully, Earth’s atmosphere and magnetic field protect us from most of the storms produced by the Sun.
Now, space weather near a black hole would be interesting if the black hole is consuming matter. It could be millions — perhaps even billions — of times stronger than the Sun’s, depending on how close the planet is. Even though black holes don’t emit light themselves, their surroundings can be very bright and hot. Accretion disks — swirling clouds of matter falling toward black holes — emit huge amounts of radiation and particles and form incredible magnetic fields. In them, you’d also have to worry about debris traveling at nearly the speed of light, slamming into your planet. It’d be hard to avoid getting hit by anything coming at you that fast!
2. Hello? Can you still hear us?
We launched the Parker Solar Probe to learn more about the Sun. If you lived on a world around a supermassive black hole, you'd probably want to study it too. But it would be a lot more challenging!
You’d have to launch satellites that could withstand the extreme space weather. And then there would be major communication issues — a time-delay in messages sent between the spacecraft and your planet.
On Earth we experience time gaps when talking to missions on Mars. It takes up to 22 minutes to hear back from them. Around a black hole, that effect would be much more extreme. Objects closer to the black hole would experience time differently, making things seem slower than they actually are. That means the delay in communications with a satellite launched toward a black hole would become longer and longer as it got closer and closer. By the time you hear back from your satellite, it might be gone!
3. Can someone turn off the lights?
Supermassive black holes at the centers of galaxies typically have a lot of nearby stars. In fact, if you were to live on a planet near the center of the Milky Way, there would be so many stars you could read at night without using electricity.
That sounds kind of cool, right? Maybe — unless your planet is actually orbiting the supermassive black hole. Being that close, the light from all those stars would be concentrated and amplified due to the extreme gravity around the black hole, making the light stronger and even causing scary beams of strong radiation. You would want to have a bucket of sunscreen ready to apply often — or simply never leave your home.
4. Did someone leave the oven on?
And not only would it be really bright, it would also be really toasty, thanks to radioactive heating! Those stars hanging around the black hole emit not just light but ghostly particles called neutrinos— speedy, tiny particles that weigh almost nothing and rarely interact with anything. While neutrinos coming from our Sun aren't enough to harm us, the volume that would be coming from the cluster of stars near a black hole would be enough to radioactively heat up whatever they slam into.
The planet would absorb neutrinos, which would, in turn, warm up the core of the planet eventually making it unbearably hot. It would be like living in a nuclear reactor. At least you’d be warm and could toss your winter coats?
5. You are what you eat?
If your planet got too close to a black hole, you’d likely face a gruesome fate. The forces from the black hole's gravity stretch matter, essentially turning it into a noodle. We call this spaghettification. (Beware the cosmic pasta-making machine?) Imagine yourself falling feet-first toward a black hole. Spaghettification happens because the gravity at your feet is sooooo much stronger than that at your head that you start to stretch out!
Maybe you wish you could simply drift around a black hole in a spacecraft and enjoy the view, or travel through one like science fiction depicts. Sadly, even if we had the means to get close to a black hole, it clearly wouldn’t be that simple or even very enjoyable.
Watch Dr. Jeremy Schnittman’s talk on the science behind the black hole from the movie Interstellar here.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Hubble’s 5 Weirdest Black Hole Discoveries
Our Hubble Space Telescope has been exploring the wonders of the universe for nearly 30 years, answering some of our deepest cosmic questions. Some of Hubble’s most exciting observations have been about black holes — places in space where gravity pulls so much that not even light can escape. As if black holes weren’t wild enough already, Hubble has helped us make discoveries that show us they’re even weirder than we thought!
Supermassive Black Holes Are Everywhere
First, these things are all over the place. If you look at any random galaxy in the universe, chances are it has a giant black hole lurking in its heart. And when we say giant, we’re talking as massive as millions or even billions of stars!
Hubble found that the mass of these black holes, hidden away in galactic cores, is linked to the mass of the host galaxy — the bigger the galaxy, the bigger the black hole. Scientists think this may mean that the black holes grew along with their galaxies, eating up some of the stuff nearby.
Some Star Clusters Have Black Holes
A globular cluster is a ball of old, very similar stars that are bound together by gravity. They’re fairly common — our galaxy has at least 150 of them — but Hubble has found some black sheep in the herd. Some of these clusters are way more massive than usual, have a wide variety of stars and may even harbor a black hole at the center. This suggests that at least some of the globular clusters in our galaxy may have once been dwarf galaxies that we absorbed.
Black Hole Jets Regulate Star Birth
While black holes themselves are invisible, sometimes they shoot out huge jets of energy as gas and dust fall into them. Since stars form from gas and dust, the jets affect star birth within the galaxy.
Sometimes they get rid of the fuel needed to keep making new stars, but Hubble saw that it can also keep star formation going at a slow and steady rate.
Black Holes Growing in Colliding Galaxies
If you’ve ever spent some time stargazing, you know that staring up into a seemingly peaceful sea of stars can be very calming. But the truth is, it’s a hectic place out there in the cosmos! Entire galaxies — these colossal collections of gas, dust, and billions of stars with their planets — can merge together to form one supergalaxy. You might remember that most galaxies have a supermassive black hole at the center, so what happens to them when galaxies collide?
In 2018, Hubble unveiled the best view yet of close pairs of giant black holes in the act of merging together to form mega black holes!
Gravitational Wave Kicks Monster Black Hole Out of Galactic Core
What better way to spice up black holes than by throwing gravitational waves into the mix! Gravitational waves are ripples in space-time that can be created when two massive objects orbit each other.
In 2017, Hubble found a rogue black hole that is flying away from the center of its galaxy at over 1,300 miles per second (about 90 times faster than our Sun is traveling through the Milky Way). What booted the black hole out of the galaxy’s core? Gravitational waves! Scientists think that this is a case where two galaxies are in the late stages of merging together, which means their central black holes are probably merging too in a super chaotic process.
Want to learn about more of the highlights of Hubble’s exploration? Check out this page! https://www.nasa.gov/content/goddard/2017/highlights-of-hubble-s-exploration-of-the-universe
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
Got a question about black holes? Let’s get to the bottom of these odd phenomena. Ask our black hole expert anything!
Black holes are mystifying yet terrifying cosmic phenomena. Unfortunately, people have a lot of ideas about them that are more science fiction than science. Don’t worry! Our black hole expert, Jeremy Schnittman, will be answering your your questions in an Answer Time session on Wednesday, October 2 from 3pm - 4 pm ET here on NASA’s Tumblr! Make sure to ask your question now by visiting http://nasa.tumblr.com/ask!
Jeremy joined the Astrophysics Science Division at our Goddard Space Flight Center in 2010 following postdoctoral fellowships at the University of Maryland and Johns Hopkins University. His research interests include theoretical and computational modeling of black hole accretion flows, X-ray polarimetry, black hole binaries, gravitational wave sources, gravitational microlensing, dark matter annihilation, planetary dynamics, resonance dynamics and exoplanet atmospheres. He has been described as a “general-purpose astrophysics theorist,” which he regards as quite a compliment.
Fun Fact: The computer code Jeremy used to make the black hole animations we featured last week is called “Pandurata,” after a species of black orchid from Sumatra. The name pays homage to the laser fusion lab at the University of Rochester where Jeremy worked as a high school student and wrote his first computer code, “Buttercup.” All the simulation codes at the lab are named after flowers.
Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com
New Zealand was lovely, but I already touched on what I’d be tempted to talk about with my Southern Stars episode. A person I interviewed as a potential new housemate gave me the idea for this episode because the joy of outer space is truly everywhere and anywhere. The field of astrogeology was not something I had heard of before, though I had indirectly heard of Eugene Shoemaker. I knew the comet Shoemaker-Levy 9 was named after him (and Carolyn Shoemaker, his wife). It turns out he basically founded the modern field of astrogeology! So I talk about him for quite a while, too.
Below the cut are the glossary, transcript, sources, and music credits. Send me any topic suggestions via Tumblr message (you don’t need an account to do this, just submit as anonymous). You can also tweet at me on Twitter at @HDandtheVoid, or you can ask me to my face if you know me in real life. Subscribe on iTunes to get the new episodes of my semi-monthly podcast, and please please please rate and review it. Go ahead and tell friends if you think they’d like to hear it, too!
(The next episode is definitely going to be on famous comets, and I’m hoping to publish that episode in May.)
Glossary
active galaxy - a galaxy with a small core of emission embedded at the center. This core is typically very variable and very bright compared to the rest of the galaxy. These galaxies emit much more energy than they should; this excess energy is found in the infrared, radio, UV, and X-ray regions of the electromagnetic spectrum.
black hole - a region of spacetime where a great deal of mass and energy have been compressed into a relatively small space. Black holes exert such strong gravitational effects that no mass or energy, not even light, can escape from inside them. There are supermassive black holes in galaxies that contribute to the development and life cycle of galaxies.
blazar - a subcategory of active galaxy, it is an extremely bright, distant object, powered by a black hole, which emits massive amounts of energy. It is distinct from a quasar because it is even brighter.
interferometry - a group of techniques to extract information from superimposing electromagnetic waves to create interference. In radio astronomy, this is done by using a wide spread of receivers to look at the same distant object, then bringing that data together with a correlator that can create a larger, clearer picture than an individual radio telescope alone could.
Messier object - a deep-sky object included on a list of 103-110 deep-sky objects made by Charles Messier and his colleagues in the 18th century in an attempt to prevent fuzzy, bright objects from being confused with comets.
torus - a donut shape.
quasar - a distant, massive celestial object that emits extremely large amounts of energy. These star-like objects may reflect a stage in the evolution of some galaxies.
Script/Transcript
Sources
Black Holes, explained via National Geographic
What Is a Black Hole? via NASA
Black Holes via NASA
Black Hole via Swinburne University of Technology
Darkness Visible, Finally: Astronomers Capture First Ever Image of a Black Hole via the New York Times (April 2019)
Event Horizon Telescope
Astronomers Capture First Image of a Black Hole via ESO (April 2019)
How They Took the First Picture of a Black Hole via New York Times (April 2019)
Intro Music: ‘Better Times Will Come’ by No Luck Club off their album Prosperity
Filler Music: ‘Flame On Flame (A Slow Dirge)’ by Kishi Bashi off his album Sonderlust
Outro Music: ‘Fields of Russia’ by Mutefish off their album On Draught
Merging Galaxies Have Enshrouded Black Holes
NASA - NuStar Mission patch. May 9, 2017 Black holes get a bad rap in popular culture for swallowing everything in their environments. In reality, stars, gas and dust can orbit black holes for long periods of time, until a major disruption pushes the material in. A merger of two galaxies is one such disruption. As the galaxies combine and their central black holes approach each other, gas and dust in the vicinity are pushed onto their respective black holes. An enormous amount of high-energy radiation is released as material spirals rapidly toward the hungry black hole, which becomes what astronomers call an active galactic nucleus (AGN). A study using NASA’s NuSTAR telescope shows that in the late stages of galaxy mergers, so much gas and dust falls toward a black hole that the extremely bright AGN is enshrouded. The combined effect of the gravity of the two galaxies slows the rotational speeds of gas and dust that would otherwise be orbiting freely. This loss of energy makes the material fall onto the black hole.
Image above: This illustration compares growing supermassive black holes in two different kinds of galaxies. A growing supermassive black hole in a normal galaxy would have a donut-shaped structure of gas and dust around it (left). In a merging galaxy, a sphere of material obscures the black hole (right). Image Credits: National Astronomical Observatory of Japan. “The further along the merger is, the more enshrouded the AGN will be,” said Claudio Ricci, lead author of the study published in the Monthly Notices Royal Astronomical Society. “Galaxies that are far along in the merging process are completely covered in a cocoon of gas and dust.” Ricci and colleagues observed the penetrating high-energy X-ray emission from 52 galaxies. About half of them were in the later stages of merging. Because NuSTAR is very sensitive to detecting the highest-energy X-rays, it was critical in establishing how much light escapes the sphere of gas and dust covering an AGN. The study was published in the Monthly Notices of the Royal Astronomical Society. Researchers compared NuSTAR observations of the galaxies with data from NASA’s Swift and Chandra and ESA’s XMM-Newton observatories, which look at lower energy components of the X-ray spectrum. If high-energy X-rays are detected from a galaxy, but low-energy X-rays are not, that is a sign that an AGN is heavily obscured.
NASA’s NuSTAR telescope. Image Credit: NASA
The study helps confirm the longstanding idea that an AGN’s black hole does most of its eating while enshrouded during the late stages of a merger. “A supermassive black hole grows rapidly during these mergers,” Ricci said. “The results further our understanding of the mysterious origins of the relationship between a black hole and its host galaxy.” NuSTAR is a Small Explorer mission led by Caltech and managed by NASA’s Jet Propulsion Laboratory for NASA’s Science Mission Directorate in Washington. NuSTAR was developed in partnership with the Danish Technical University and the Italian Space Agency (ASI). The spacecraft was built by Orbital Sciences Corp., Dulles, Virginia. NuSTAR’s mission operations center is at UC Berkeley, and the official data archive is at NASA’s High Energy Astrophysics Science Archive Research Center. ASI provides the mission’s ground station and a mirror archive. JPL is managed by Caltech for NASA. Related link: Monthly Notices of the Royal Astronomical Society: https://academic.oup.com/mnras/article/468/2/1273/2939810/Growing-supermassive-black-holes-in-the-late For more information on NuSTAR, visit: http://www.nasa.gov/nustar http://www.nustar.caltech.edu Images (mentioned), Text, Credits: NASA/Tony Greicius/JPL/Elizabeth Landau. Greetings, Orbiter.ch Full article