Astronomers using the James Webb Space Telescope have discovered a never-before-seen cosmic object in the early universe powered by a massive central black hole.
The object, dubbed MoM-BH*-1, appears as a hybrid between a giant star and a supermassive black hole, stretching across an area as large as our entire solar system.
Researchers were shocked to discover that the bizarre red dot emits 100 billion times more energy than any single star can physically generate through standard stellar processes.
"That means you can't be powering this by nuclear fusion, which is the energy source that sits at the heart of all the stars we have," said lead author Dr Rohan Naidu of the Massachusetts Institute of Technology and the University of Hawai'i.
Writing in the journal Nature, Dr Naidu and his colleagues proposed that MoM-BH*-1 represents a completely new class of astronomical body known as a "black hole star."
The team estimates that the central black hole has a mass 100,000 times greater than our sun, producing massive amounts of energy that shine through a surrounding cocoon of dense hydrogen gas.
Astronomers spotted the object while conducting the "Miracle or Mirage" survey, an initiative using the James Webb Space Telescope to search for the earliest galaxies formed after the Big Bang.
While cosmic dust clouds frequently absorb light and give distant celestial objects a crimson tint similar to wildfire smoke over a city, this object exhibited unique spectral properties.
"The way its light is almost entirely red and abruptly disappears below a certain wavelength is so dramatic that there is no comparison among any prior set of objects," Dr Naidu said.
The sharp drop-off in light wavelengths, known as a Balmer Break, occurs when dense atmospheric gases absorb photons. In astrophysics, a Balmer Break is a standard spectral feature caused by hydrogen gas in stellar atmospheres, commonly observed in mature stars such as Vega in the constellation Lyra.
However, the Balmer Break measured from MoM-BH*-1 was the deepest ever recorded by astronomers, ruling out a traditional star as the light source.
Spectral analysis and element composition
Spectroscopic analysis revealed another anomaly: the object's light contained no heavy metals or chemical signatures typical of known stars, showing only pure hydrogen and helium.
"It is a very special thing to find an object with no comparison given the vast stores of data on billions of stars, galaxies, and black holes that we have in astronomical archival databases," Dr Naidu said.
"But it made us wonder if we were seeing a new kind of 'stellar atmosphere', but on a spectacular scale," he added.
Computer simulations match black hole cocoon
To explain the object's extreme brightness and unusual spectral properties, the research team ran extensive computer simulations testing various astronomical configurations.
The simulations only matched real-world observations when the star was replaced by an active black hole enveloped in dense hydrogen gas.
The closest matching model placed a central black hole with 100,000 times the mass of the sun inside a hydrogen cloud so dense that its outer perimeter resembles the surface of a solar-system-sized star.
"The rapidly feeding black hole at its centre is the source of its energy," Dr Naidu explained.
"The energy may be transmitted in the form of radiation or winds or shocks that slam against the dense shrouds of gas enveloping the black hole," he said.
This mechanism accounts for the object's extreme luminosity, the record-breaking Balmer Break, and the complete absence of elements heavier than hydrogen and helium.
Solving the mystery of little red dots
Researchers believe MoM-BH*-1 may not be unique, but rather the first identified example of hundreds of black hole stars scattered across the early cosmos.
The James Webb Space Telescope has identified hundreds of unexplained "little red dots" in deep-space images dating to the first hundred million years of the universe, which disappear in later cosmic epochs.
"Black Hole Star may lie at the heart of every Little Red Dot," Dr Naidu said, suggesting these objects have been hiding in plain sight.
"The redness of the little red dots is because their blue light is soaked up by the dense shrouds of gas blanketing the Black Hole Star," he explained.
"All the peculiarities and puzzles surrounding the Little Red Dots begin to make sense once you place black hole stars at their centres," Dr Naidu said.
Origins and formation of cosmic black holes
Black holes are regions of space with gravitational fields so intense that no matter or electromagnetic radiation, including light, can escape their pull.
Acting as intense gravitational anchors, black holes devour surrounding gas and dust, providing the core gravitational pull around which stars in galaxies orbit.
Astrophysicists still seek to understand how early black holes formed, evaluating two primary theories for supermassive black hole seeds.
One model suggests a massive primordial gas cloud up to 100,000 times the mass of the sun directly collapses into a seed black hole, which then merges with other seeds to form the supermassive black holes found at the centers of massive galaxies.
An alternative theory posits that seeds originate from giant stars approximately 100 times the sun's mass that exhaust their fuel, collapse into black holes, and trigger supernova explosions that shed their outer layers into deep space.
