Black holes

Researchers at MIT have discovered the composition of primordial black holes, “potentially discovering an entirely new type of exotic black hole in the process,” reports Jacopo Prisco for CNN. “We were making use of Stephen Hawking’s famous calculations about black holes, especially his important result about the radiation that black holes emit,” says Prof. David Kaiser. “These exotic black holes emerge from trying to address the dark matter problem — they are a byproduct of explaining dark matter.”

Prof. Netta Engelhardt talks to New Scientist’s Thomas Lawton about the possibility of singularities existing outside black holes. Theorists can now probe singularities from a deeper perspective, using insights into the possible quantum foundations of gravity. This new approach “flips the script” on how we think about singularities, says Engelhardt.

MIT astronomers measured a black hole’s spin for the first time by tracking the X-ray flashes produced by a black hole following a tidal disruption event, reports Interesting Engineering’s Mrigakshi Dixit. “The spin value of a black hole tells us about how it evolved over the age of the universe,” explains Research Scientist Dheeraj Pasham. 

MIT astronomers have found a new way to measure how fast a black hole spins, observing the aftermath of a black hole tidal disruption event with a telescope aboard the International Space Station, reports Laura Baisas for Popular Science. “The only way you can do this is, as soon as a tidal disruption event goes off, you need to get a telescope to look at this object continuously, for a very long time, so you can probe all kinds of timescales, from minutes to months,” said Research Scientist Dheeraj Pasham.

Astronomers at MIT and elsewhere have determined how to measure the spin of a nearby supermassive black hole using a new calculation method, reports Isaac Schultz for Gizmodo. The team “managed to deduce a supermassive black hole’s spin by measuring the wobble of its accretion disk after a star has been disrupted—a polite word for torn up—by the gigantic object,” explains Schultz. “They found the black hole’s spin was less than 25% the speed of light—slow, at least for a black hole.” 

Researchers at MIT have discovered that a previously witnessed supermassive black hole has “a smaller companion black hole zipping around it, kicking up dust every time it goes by,” reports John Wenz for Astronomy. This discovery “shakes up our thinking of what the environment at the core of the galaxy looks like,” explains Wenz. “Instead of a simple disk of matter surrounding the central black hole, steadily swirling across its event horizon, the centers of galaxies could host multiple black holes of different sizes, leading to more complex feeding behavior.”

Astronomers from MIT and other institutions have found that periodic eruptions from a supermassive black hole located in a galaxy about 800 million light-years from Earth could be caused by a, “second, smaller black hole slamming into a disk of gas and dust, or ‘accretion disk,’ surrounding the supermassive black hole, causing it to repeatedly ‘hiccup’ out matter,” writes Rob Lea for Space.com. 

Senior Research Scientist Lisa Barsotti speaks with MIT Technology Review reporter Sophia Chen about how she and her colleagues developed a new device that uses quantum squeezing to help the LIGO detectors identify more celestial events, such as black hole mergers and neutron star collisions. “With these latest squeezing innovations, installed last year, the collaboration expects to detect gravitational waves up to 65% more frequently than before,” Chen explains.

Prof. Erin Kara speaks with Quanta Magazine reporter Michael Greshko about her career as an observational astrophysicist and her work to better understand how black holes behave and reshape galaxies across the universe. “The thing that really got me excited about pursuing astronomy was the discovery aspect: It was just super thrilling to be the first person to look at light that was released from around a black hole a billion years ago,” says Kara.

Researchers at MIT have discovered 18 supermassive black holes that “are tearing apart nearby stars in ‘oddball’ tidal disruption events,” reports Ava Berger for The Boston Globe. Graduate student Megan Masterson says, “the events are powerful tools to understand the most extreme parts of our universe. They happen about once every 50,000 years, and help scientists learn more about the supermassive black hole at the center of the Milky Way, and black holes in general.”

MIT researchers have discovered 18 new tidal disruption events (TDEs), “which are huge bursts of energy released as a star is shredded by a black hole,” reports Jess Thomson for Newsweek. “These new discoveries have also helped scientists learn more about what TDEs really are and where they occur,” explains Thomson. “The previous stock of TDEs had only been found in a rare form of galaxy known as a ‘post-starburst’ system, which once created a number of stars but has since stopped.”

Researchers from MIT and elsewhere have proposed a new method to look for primordial black holes (PMBs), reports Jackie Appel for Popular Mechanics. “If there are as many as the team thinks there should be, and they interact with gravity as we expect them to, they should be zooming around in a way that some of them should pass close by various objects in our solar system – including Earth,” explains Appel. “And if that happens, it should actually be enough to disturb the natural orbits of these objects in a way that we can measure.” 

Using the James Webb Space Telescope (JWST), astronomers at MIT and elsewhere have discovered that the young cosmos hosted a large number of tempestuous galaxies with large black holes at their cores, reports Charlie Wood for Quanta Magazine. “The exact numbers and the details of each object remain uncertain, but it’s very convincing that we’re finding a large population of accreting black holes,” says Prof. Anna-Christina Eilers. “JWST has revealed them for the first time, and that’s very exciting.”

Science News reporter James Riordon writes that by employing a new technology called frequency-dependent squeezing, LIGO detectors should now be able to identify about 60 more mergers between massive objects like black holes and neutron stars than before the upgrade. Senior research scientist Lisa Barsotti, who oversaw the development of this new technology, notes that even next-generation gravitational wave detectors will be able to benefit from quantum squeezing. “The beauty is you can do both. You can push the limit of what is possible from the technology of laser power and mirror [design],” Barsotti explains, “and then do squeezing on top of that.”

MIT researchers Lisa Barsotti, Deep Chatterjee and Victoria Xu speak with Curiosity Stream about how developments in gravitational wave detection are enabling a better understanding of the universe. Barsotti notes that in the future, gravitational wave science should help enable us to, “learn more about dark matter about primordial black holds to try to solve some of the biggest mysteries in our universe.” Xu notes, “the detection of gravitational waves is a completely new window that has opened into our universe.”