Imagine you are a neutron star. You’re happily floating in space, too old to fuse nuclei in your core anymore, but the quantum pressure of your neutrons and quarks easily keeps you from collapsing under your own weight. You look forward to a long stellar retirement of gradually cooling down. Then one day you are struck by a tiny black hole. This black hole only has the mass of an asteroid, but it causes you to become unstable. Gravity crushes you as the black hole consumes you from the inside out. Before you know it, you’ve become a black hole.
Continue reading “What's the Connection Between Stellar-Mass Black Holes and Dark Matter?”Did Supermassive Black Holes Form Directly From Dark Matter?
Supermassive black holes are just a little bit too supermassive – astronomers have difficulty explaining how they got so big so quickly in the early universe. So maybe it’s time for a new idea: perhaps giant black holes formed directly from dark matter.
Continue reading “Did Supermassive Black Holes Form Directly From Dark Matter?”Cygnus X-1 was the First Black Hole Ever Found. New Measurements Show it's Much More Massive Than Previously Believed
In 1964 two Aerobee suborbital rockets were launched with the goal of mapping x-ray sources in the sky. Each rocket contained a directed Geiger counter, so that as the rocket rotated at the peak of its trajectory to measure the direction of x-ray sources. The project discovered eight x-ray sources, including a particularly bright one in the constellation Cygnus. It became known as Cygnus X-1.
Continue reading “Cygnus X-1 was the First Black Hole Ever Found. New Measurements Show it's Much More Massive Than Previously Believed”A Cluster of Black Holes Found Inside a Globular Cluster of Stars
Black holes come in at least two sizes: small and large. Small black holes are formed from stars. When a large star reaches the end of its life, it typically ends in a supernova. The remnant core then collapses under its own weight, forming a black hole or neutron star. Small stellar-mass black holes are typically tens of solar masses. Large black holes lurk in the centers of galaxies. These supermassive black holes can be millions or billions of solar masses. They formed during the early universe and triggered the formation and evolution of galaxies around them.
Continue reading “A Cluster of Black Holes Found Inside a Globular Cluster of Stars”Black Holes Simulated in a Tank of Water Reveals “Backreaction” for the First Time
It’s hard to make a black hole in the lab. You have to gather up a bunch of mass, squeeze it until it gravitationally collapses on itself, work, work, work. It’s so hard to do that we’ve never done it. We can, however, make a simulated black hole using a tank of water, and it can tell us interesting things about how black holes work.
Continue reading “Black Holes Simulated in a Tank of Water Reveals “Backreaction” for the First Time”When Galaxies Collide, Black Holes Don’t Always Get the Feast They Were Hoping for
What happens when galaxies collide? Well, if any humans are around in about a billion years, they might find out. That’s when our Milky Way galaxy is scheduled to collide with our neighbour the Andromeda galaxy. That event will be an epic, titanic, collision. The supermassive black holes at the center of both galaxies will feast on new material and flare brightly as the collision brings more gas and dust within reach of their overwhelming gravitational pull. Where massive giant stars collide with each other, lighting up the skies and spraying deadly radiation everywhere. Right?
Maybe not. In fact, there might be no feasting at all, and hardly anything titanic about it.
Continue reading “When Galaxies Collide, Black Holes Don’t Always Get the Feast They Were Hoping for”In Theory, Supermassive Black Holes Could get Even More Supermassive
Our universe contains some enormous black holes. The supermassive black hole in the center of our galaxy has a mass of 4 million Suns, but it’s rather small as galactic black holes go. Many galactic black holes have a billion solar masses, and the most massive known black hole is estimated to have a mass of nearly 70 billion Suns. But just how big can a black hole get?
Continue reading “In Theory, Supermassive Black Holes Could get Even More Supermassive”Missing: Supermassive Black Hole With up to 100 BILLION Times the Mass of the Sun
The massive galaxy cluster Abell 2261 should have a supermassive black hole in its center. But it doesn’t. Astronomers have looked everywhere – even between the couch cushions. What’s going on?
Continue reading “Missing: Supermassive Black Hole With up to 100 BILLION Times the Mass of the Sun”A Galaxy is Making New Stars Faster Than its Black Hole Can Starve Them for Fuel
A monster lurks at the heart of many galaxies – even our own Milky Way. This monster possesses the mass of millions or billions of Suns. Immense gravity shrouds it within a dark cocoon of space and time – a supermassive black hole. But while hidden in darkness and difficult to observe, black holes can also shine brighter than an entire galaxy. When feeding, these sleeping monsters awaken transforming into a quasar – one of the Universe’s most luminous objects. The energy a quasar radiates into space is so powerful, it can interfere with star formation for thousands of light years across their host galaxies. But one galaxy appears to be winning a struggle against its awoken blazing monster and in a recent paper published in the Astrophysical Journal, astronomers are trying to determine how this galaxy survives.
Continue reading “A Galaxy is Making New Stars Faster Than its Black Hole Can Starve Them for Fuel”Black Holes Gain new Powers When They Spin Fast Enough
General relativity is a profoundly complex mathematical theory, but its description of black holes is amazingly simple. A stable black hole can be described by just three properties: its mass, its electric charge, and its rotation or spin. Since black holes aren’t likely to have much charge, it really takes just two properties. If you know a black hole’s mass and spin, you know all there is to know about the black hole.
Continue reading “Black Holes Gain new Powers When They Spin Fast Enough”