Fe Kα · 6.4 keV
The densest objects we know of, and the instruments built to watch them: X-ray observatories, interferometers, and the Event Horizon Telescope.
Black Holes
There is a question that often comes up at every public talk I do, and I have never had a good answer to it—well, not an entirely confident one. What's inside a black hole? The textbook reply is a singularity. Cross the event horizon, and everything falls inward to a point of…
For more than two decades, the quasar PHL 1811 has been considered the prototype of a rare class of "intrinsically X-ray weak" quasars, thought to produce unusually little X-ray radiation. But in 2024, the Einstein Probe spacecraft caught the object in a bright X-ray flare. In a…
A distant black hole star is providing strong evidence that these objects lie at the hearts of the mysterious little red dots found shortly after the Big Bang by the James Webb Space Telescope.
Little red dots have puzzled astronomers since their discovery in James Webb Space Telescope (JWST) data from the universe's deep past. Their "powering engines" might resemble a newly discovered phenomenon dubbed a "black hole star"—an early, rapidly growing black hole wrapped…
An international team of astronomers led by the Max Planck Institute for Extraterrestrial Physics has identified three actively accreting supermassive black holes in the galaxy J0148-4214. Matter is falling into the black holes from accretion disks surrounding them.
Thermodynamics can describe the mechanics of black holes that change over time
Astronomers have nearly doubled the number of known cosmic X-ray sources.
Wei Hong et al 2026 ApJS 284 51 Resonance between gravitational waves and magnetic fields may produce a faint radio signal in pulsar magnetospheres; current searches are approaching the sensitivity necessary to detect this signal.
Some black holes roaming the Universe today may actually be older than the Big Bang. A new cosmic “bounce” model suggests the Universe expanded from an earlier contracting phase, allowing ancient black holes to survive the transition as cosmic fossils. These relics could…
Correcting heat-induced distortions in interferometer mirrors will dramatically increase the sensitivity of gravitational-wave detectors
Using the NASA/ESA/CSA James Webb Space Telescope, an international team of astronomers have discovered that dust and water can form and survive surprisingly close to the supermassive black hole at the centre of our Milky Way galaxy. The observations reveal that the evolved star…
A quasar is a supermassive black hole in the act of feeding, and it’s so bright that it drowns out the galaxy it sits in. That is a nuisance if you want to weigh the galaxy and weighing it is exactly what you need to do to understand how black holes and the host galaxies grew up…
Some 1.3 billion years ago, when multicellular organisms were just emerging on Earth and life was still confined to the ocean, two behemoth black holes smashed together in a far-flung galaxy. The collision was so powerful that it jolted the universe, creating a ripple in the…
Mian Zhu and Yi-Fu Cai 2026 ApJL 1004 L34 In a cosmology framework that proposes the universe began with a period of contraction before the Big Bang, researchers find that high-frequency gravitational waves oscillate in a way that is potentially detectable.
A supermassive black hole has been found lurking about 30,000 light-years from the center of its galaxy—the first dormant black hole detected so far from a galactic core. It revealed itself only after shredding a passing star and producing a brief, brilliant flare. Astronomers…
Mayura Balakrishnan et al 2026 ApJ 1003 128 Sgr A East strongly overlaps with plasma associated with the Milky Way’s central supermassive black hole, but new efforts to disentangle this emission have successfully isolated the remnant’s emission.
Properties of a merger remnant can be predicted using a simple entropy-maximization principle
Primordial black holes may occasionally pass through white dwarf stars and trigger enormous Type Ia supernova explosions. Researchers found that these events could explain chemical patterns seen in supernova remnants, nearby explosions, and stars across the Milky Way.
Jiazheng Zhu et al 2026 ApJL 1004 L10 Discovered just 6 billion years after the Big Bang, AT2025wet is the highest-redshift non-jetted tidal disruption event known, allowing researchers to probe the missing-energy puzzle.
A black hole observed during a dramatic 2023 eruption did not simply devour gas from its nearby companion star. It also expelled large amounts of material through powerful jets and winds, even after the outburst had nearly faded. The results suggest black holes may continue…
A recent Focus Issue of the Astrophysical Journal Letters introduces the fourth version of the gravitational wave transient catalog from the LIGO, Virgo, and KAGRA collaborations.
NASA’s Swift Observatory observed a supermassive black hole ripping apart a star more than 30,000 light-years from the center of a distant galaxy. The extraordinary flare briefly outshone its entire host galaxy in ultraviolet light and revealed a black hole about a million times…
What powers the prominent helium emission from Hebe, a gas clump seen just 450 million years after the Big Bang?
Nir Guttman et al 2026 ApJ 996 144 An analysis of the fourth gravitational wave catalog supports the existence of a gap at 45 solar masses in the secondary black hole mass distribution, among other findings.
One of the biggest mysteries in modern astronomy is how the Universe managed to grow enormous black holes so quickly.
Hydrocarbons keep turning up in surprising places. This time, they've been found near a pair of accreting supermassive black holes 3 billion years after the Big Bang.
JWST has captured unusually detailed images of gas feeding the supermassive black hole at the center of NGC 4696. A vast filament appears to funnel material into an 800-light-year-wide spinning disk, where gas races around at up to 600 kilometers per second. The findings suggest…
Region near the "surface of no return" was previously only accessible with theoretical models
The massive globular star cluster Omega Centauri has puzzled astronomers for decades. It should be filled with black holes left behind by exploding stars, yet evidence for them is scarce. Now, astronomers using archival data from the NASA/ESA Hubble Space Telescope and…
Scientists have developed a new framework that could finally apply the laws of thermodynamics to real, ever-changing black holes instead of only perfectly stable ones. The advance may improve our understanding of black hole mergers, evaporation, and the powerful gravitational…
Researchers have recreated the physics of extracting energy from a spinning black hole using a stationary device that produces synthetic ultrafast rotation. The achievement transforms a long-standing theoretical idea into a practical experiment and could inspire new advances in…
What's behind the population of compact, reddish objects spotted by JWST? Two recent research articles have explored theories involving young globular clusters and little red dots with little blue companions.
Astrobites reports on the first case of a supermassive black hole discovered away from its galaxy’s center, exposed when it tore apart a star in a tidal disruption event.
NASA ·
NOIRLab/NSF/AURA ·
APOD · Marcin Rosadziński ·
The vocabulary below is the actual list this subject is matched on — nothing is hidden and nothing is inferred. Terms on the top line settle it on their own; the second line counts, but needs company.
black holeevent horizonaccretion diskaccretion discsupermassivetidal disruption eventgravitational waveligovirgo detectorkagrasagittarius aquasarblazarrelativistic jetergospheresingularityintermediate-mass black holebinary black holeneutron star merger
general relativityspacetime curvatureactive galactic nucleusagnx-ray binarymicroquasarlisa missionpulsar timing arrayframe dragging
