Black Hole Flips Between Two Modes, Baffles Scientists

For three years, NASA scientists watched a black hole do something they'd never seen before: flip back and forth between two completely different behaviors like someone hitting a cosmic light switch.

The black hole system 4U 1630−472, about ten times the mass of our Sun, doesn't just swallow matter from space. Instead, it alternates between launching high-speed plasma jets and blasting powerful winds, operating like a perfectly timed seesaw that never does both at once.

Scientists used NASA's NICER X-ray telescope and the MeerKAT radio array to track this behavior across 28 observations between 2020 and 2023. Every single time the X-ray wind appeared in their data, the radio jet vanished. When the jet fired up, the wind disappeared completely.

"We're seeing what could be described as an energetic tug-of-war inside the black hole's accretion flow," explained Jiachen Jiang from the University of Warwick. This isn't random behavior. It's a regulated switching mechanism scientists are only beginning to understand.

The black hole pulls material from a nearby companion star into a spinning disk of superheated gas. Instead of just consuming everything, it channels that energy into one of two escape routes, but apparently can't power both simultaneously.

In one observation, NICER recorded winds traveling at 300 kilometers per second while MeerKAT detected no radio jet whatsoever. Days later at nearly identical energy levels, the system showed a strong radio jet but zero wind activity.

Why This Inspires

This discovery isn't just fascinating science. It could explain how galaxies grow and evolve over billions of years.

Black holes don't just destroy matter. They redistribute it across space, controlling how gas and dust (the building blocks of stars) spread through galaxies. This jet-versus-wind switching mechanism might determine where new stars can form and how fast galaxies develop.

The finding challenges what scientists previously believed about these cosmic engines. They assumed jets and winds might operate together, but this strict either-or behavior suggests a deeper physical constraint tied to magnetic fields and energy distribution.

Understanding this switching pattern could help astronomers predict how supermassive black holes at galaxy centers influence star formation across the universe. What looks like indecision is actually precision engineering on a cosmic scale.

The team continues monitoring 4U 1630−472 to understand what triggers each switch and whether this behavior applies to all black holes or just specific types.