Astronomy and astrophysics

After analyzing data from the LIGO, Virgo and KAGRA gravitational wave detectors, MIT researchers have found that 14% of black holes may be second-generation, formed by the merger of two smaller black holes, writes Gayoung Lee for Gizmodo. The scientists “created an analytic model to capture the kind of wobble that would have emerged from second-generation black holes. Around 14% of merging black holes followed this pattern, and the second-generation black holes identified had a very specific range of masses, at around 20 solar masses or 40 solar masses and above,” Lee explains.  

Prof. David Kaiser joins GBH “Particles of Thought” podcast host Dr. Hakeem Oluseyi to discuss his hunt for primordial black holes. “It’s a lot easier to find stuff coming off of a very bright, hot source, than a cold, dim one. So, the Hawking temperature of a black hole that has the same mass as our sun, or a little bigger would be so cold we would literally never be able to measure [its] radiation,” says Kaiser. “You’ll never see it [Hawking Radiation] from stellar collapse black holes, you’ll never see it from supermassive black holes, or even colder. The only hope to ever see it would be a smaller mass black hole.”

Prof. Alan Guth chats with Scientific American reporter Joseph Howlett about the future of the field of cosmology and his advice for early-career physicists for “The Young American Scientists” special section. Guth shares that thanks to advances in technology, “we’re able to unravel, to make sense out of, what we’re observing. A lot of progress has been made on those lines.” 

Scientific American reporter Clara Moskowitz spotlights a new study by Prof. Seth Lloyd that explores the feasibility of black holes sending information back in time. In the study, Lloyd and his colleagues calculate how much information can be sent backward via closed timelike curves, intensely bending, rotating space found around spinning black holes. “Spacetime can curve around so much that you can be innocently going forward in time and then you meet yourself in the past,” says Lloyd. 

GBH "Particles of Thought" host Hakeem Oluseyi interviews Prof. David Kaiser about the puzzling nature of dark matter and how its explanation may be inconsistent with our assumptions of gravity. “If we assume we really know the laws of gravity, which Einstein wrote down beautifully just over a hundred years ago in his general theory of relativity...we have reason to be confident. But what people are saying is could dark matter be the first exception to that,” says Kaiser. 

Prof. Anna Frebel speaks with Science reporter Jay Bennett about the “first unambiguous second-generation star found in an ultrafaint dwarf galaxy.” It’s a fantastic discovery,” says Frebel. “I know how hard it is to find these stars. They are so, so rare.” 

Prof. David Kaiser and graduate student Alexandra Klipfel speak with New York Times reporter Dennis Overbye about their theory that a neutrino detected zipping through the Mediterranean Sea in February 2023 may have come from an exploding primordial black hole. Kaiser and Klipfel "concluded that if primordial black holes were the explanation for long-sought dark matter, scientists should expect about 40 black-hole explosions to occur each year in every cubic light-year near the Milky Way,” Overbye notes. 

Prof. Julien de Wit speaks with Dan Rea from WBZ’s Nightside News about his team’s work developing new ways to address threats posted by small asteroids to our critical space infrastructure. “We are developing the technology here at MIT to find [asteroids] and then track them and understand if we should be caring about them,” de Wit explains. 

Prof. Julien de Wit, Research Scientist Artem Burdanov and Research Scientist Saverio Cambioni join Edgar Herwick III of GBH’s Curiosity Desk to discuss their work with planetary defense and their method for detecting and tracking smaller asteroids that could impact Earth’s critical space infrastructure. “We are swimming in an era that is data rich, and so what we do in our group and at MIT is mine that data to reveal the universe like never before,” says de Wit. “Revealing new populations of asteroids, new populations of planets, and making sense of our universe like we have never done.”

Prof. Salvatore Vitale and graduate student Jack Heinzel speak with Scientific American reporter K.R. Callaway about the LIGO-Virgo-KAGRA (LVK) Collaboration’s latest catalog of gravitational wave detections, which “more than doubles the number of gravitational-wave candidate events—and reveals unexpected complexities of merging black holes.” Says Heinzel: “We’re learning a lot of things that are qualitative and phenomenological from the catalog. Starting to see all these different structures emerge is pretty fascinating.”

Prof. Raymond Pierrehumbert and his colleagues have discovered an exoplanet orbiting a star 34 light-years from Earth that is "covered with a perpetual ocean of magma and ​enveloped by a noxious and fiercely hot sulfur-rich atmosphere," reports Will Dunham for Reuters. "The era of exoplanet discovery ⁠keeps showing us ​new kinds of worlds, indeed 'strange new worlds,' generally stranger than anything in 'Star Trek,'" says Pierrehumbert. “This offers all sorts of exciting opportunities to put together fundamental physics in very novel ways."

Prof. Nergis Mavalvala, dean of the MIT School of Science, and Prof. Salvatore Vitale join Edgar B. Herwick III of GBH’s Curiosity Desk to discuss the science behind the Laser Interferometer Gravitational-wave Observatory (LIGO) and how close we are to unraveling the secrets of the early universe. LIGO has provided the ability to “observe the universe in ways that have never been done before,” says Mavalvala. 

Using new observations from the James Webb Space Telescope (JWST), astronomers from MIT determined that asteroid 2024 YR4 will not collide with the moon, reports Hannah Devlin for The Guardian. “[Asteroid] 2024 YR4 is exceedingly faint right now, reflecting about as much light as an almond at the distance of the moon,” explain Prof. Julien de Wit and Andy Rivkin PhD '91, who co-led the observations. “Webb is the only observatory that could hope to make these measurements, as it is the only one with the required sensitivity and stability combined with precise moving-target tracking needed to follow and study objects like this.”

Prof. Anna-Christina Eilers and postdoctoral associate Rohan Naidu speak with Scientific American reporter Rebecca Boyle about the discovery and study of Little Red Dots, mysterious, red spots that showed up in images from the James Webb Space Telescope.  The dots, which astronomers dated to 600 million years after the big bang, “are in every single image the telescope takes,” says Naidu. “We have to find out about them if we want to tell a complete story about the early universe." 

Using the James Webb Telescope, postdoctoral associate Rohan Naidu and his colleagues have captured a glimpse of Galaxy MoM-z14, which existed 280 million years after the Big Bang, and could provide clues as to what the universe was like during its infancy and how it has evolved over time, reports Passant Rabbie for Gizmodo. “We can take a page from archeology and look at these ancient stars in our own galaxy like fossils from the early universe,” says Naidu. “Except in astronomy we are lucky enough to have Webb seeing so far that we also have direct information about galaxies during that time.”