Observations with the Very Large Telescope have followed the outburst cycle of Swift J1727.8−1613. Even as the X-ray intensity has declined to a few hundredths of a degree from its peak, a dense wind has been observed from the accretion disk, whose rate of mass loss may be comparable to the rate of material ingestion.
A black hole that was recorded sucking in material from a nearby star continued to spew gas into space even after its outburst had almost died down.
Astronomers led by researchers fromUniversity of Warwick Revealed new details about how systems containing Black holes They absorb and emit material. Observations show that even when such a system appears weak, it does not function as a bottomless pit that swallows all the material that comes into its vicinity. A significant portion of the material may be ejected back into space via jets and winds.
It is important to emphasize that the matter is not ejected from the black hole itself or beyond the event horizon, from which nothing can escape. The jets and winds are created in the material surrounding the black hole, before it has time to cross the event horizon and be swallowed.
An outbreak observed at different stages
through The very large telescope (VLT) of the European Southern Observatory, researchers monitored the black hole system Swift J1727.8−1613 During its major eruption in 2023.
This is a binary system inX-ray radiation, located about 8,800 light-years from Earth. It contains a black hole with an estimated mass of about ten solar masses and a low-mass companion star. The black hole's gravity pulls gas away from the star, but the gas does not fall into it immediately. It creates a Adsorption disk Rotating and hot, emitting strong radiation.
The system was discovered after it suddenly awoke in August 2023 and quickly became one of the brightest X-ray sources in Earth's sky. Its extraordinary brightness allowed astronomers to track the eruption's development in real time.
The team found that as the gas flowed toward the black hole, some of the material was ejected via fast jets and broader winds created in the accretion disk. The emissions continued even as the system weakened greatly and its activity dropped far below the levels previously associated with the formation of powerful winds.
“People often think of black holes as simply swallowing everything around them,” said lead author Dr Noel Castro Segura, a postdoctoral researcher at the University of Warwick. “What we see is a much more complex process. Material falls in, the system processes it, and a surprising amount is ejected back out.”
Not a snapshot but a film of the outbreak
The study produced one of the most detailed optical records to date of an outburst cycle in a system containing a black hole. Rather than relying on a small number of isolated observations, the astronomers followed the system through several phases of its activity.
The X-Shooter spectrograph on the VLT allowed them to observe the light emitted from the system and detect changes in the composition, temperature and velocity of the gas. This allowed them to study the black hole's feeding process as an evolving process rather than a single snapshot.
One of the most striking discoveries concerned the connection between the jet and the accretion disk. When the system emitted a strong jet, the researchers also detected significant changes in different regions of the disk. The observations provide a rare look at the possible connection between the material flowing in and the material being ejected back into space.
Cold and dense wind in the weak phase
The biggest surprise came after the main outburst phase had already ended. Even after Swift J1727.8−1613 had faded to a fraction of its peak intensity, the team detected signs of a dense wind moving outward from the system.
The light spectrum indicated a relatively cool wind, with a temperature below about 10,000 Kelvin and a speed of about 750 kilometers per second. The researchers estimate that the rate of mass loss in the wind was at least a billionth of the mass of the Sun per year—a rate similar to the rate at which material was flowing into the black hole at that time.
This means that black hole systems may continue to produce strong outflows long after the bright and dramatic phase of the outburst has ended. The total amount of material ejected from the system may be similar to the amount that eventually reaches the black hole.
“If black holes can continue to shed material even after the largest outbursts, they may be much less efficient eaters than we assumed,” Castro Segura said. He said much of the material may never reach the black hole at all, affecting the long-term evolution of binary star systems.
The end of the outbreak is also important.
The findings reinforce the picture that black hole systems are not just consumers of matter, but active systems that also return matter and energy to their environment. The emissions may affect the companion star, the rate of material transfer between the two bodies, and the future evolution of the system.
Kyle Solomons, a doctoral researcher at the University of Cape Town, explained that astronomers tend to focus on the “fireworks” that accompany the beginning of an eruption, but the new observations show that the end of the storm can also be intense. Although the X-ray radiation has dropped to a fraction of its peak intensity, the system still managed to eject a large amount of gas.
By tracking Swift J1727.8−1613 throughout almost the entire outburst cycle, the researchers documented the phases of material absorption, changes in the accretion disk, and ejection back into space. The result provides a detailed picture of how the black hole's environment responds to the incoming material and affects the space around it.
Source/Original article:
- The scientific article in the Monthly Notices of the Royal Astronomical Society
- University of Warwick Announcement
- Original article on SciTechDaily
Image caption: Artist's impression of the Swift J1727.8−1613 system, where a black hole is sucking material from a companion star and some of the material is ejected back into space via a jet and winds. Illustration: John A. Paice, Noel Castro Segura and colleagues, 2026
ALT: Simulation of the Swift J1727.8−1613 system with a black hole, companion star, accretion disk, and jet of material
Suggested filename: swift-j1727-black-hole-outflows-2026.jpg
More on the subject on the science website
- The secret energy inside every black hole is stronger than we thought
- For the first time – viewing the entire process of a star being swallowed by a black hole to the ejection of plasma jets
- Stars engulfed by a black hole release energy long after the process begins
- A black hole probably ripped apart a massive star, creating an unprecedented cosmic flash
Questions and Answers
Can matter come out of a black hole?
No. Material that has crossed the event horizon cannot escape. The material observed in the study was ejected from the accretion disk and the immediate vicinity of the black hole before crossing the event horizon.
What is Swift J1727.8−1613?
This is a binary system in which a black hole with a mass of about ten solar masses sucks gas from a companion star. The system was discovered during a powerful outburst in 2023.
What surprised the researchers?
They detected a dense wind even after the system's X-ray emission had dropped to a fraction of its peak intensity. Until now, such emissions have been associated mainly with brighter, active phases.
Why is emissions important?
If a large amount of the material is ejected before it is swallowed, the models describing the black hole's growth rate and the evolution of the Binary systems.
For the original publication: Opening the original publication
