Astronomers say the flare and a fast outflow mirror how the Sun's magnetic field snaps and launches material, physics that also drives space weather on Earth.

The magnetic physics behind solar storms appears to operate near a supermassive black hole too. Astronomers led by the Technion in Israel have reported the first detection of a telltale solar-flare pattern in the corona of a black hole, using data from the X-ray observatory XRISM, according to a Technion summary of the study.

The flare came from the black hole at the center of the galaxy NGC 3783, which holds about 28 million times the mass of the Sun. Alongside it, the team saw a very fast outflow of gas that they compare to a coronal mass ejection, the kind of eruption that triggers geomagnetic storms and auroras on Earth.

The result, published in The Astrophysical Journal Letters, connects two very different places through the same process. It is based on one flare, and the authors say more events are needed to know whether it is typical.

How the Sun Builds a Storm

The Sun's outer atmosphere, the corona, is threaded with magnetic loops. When loops twist and cross, they can suddenly snap and reconnect, releasing stored energy. That process, called magnetic reconnection, heats gas, accelerates particles and can launch billions of tons of solar material into space as a coronal mass ejection.

When a CME reaches Earth, it can drive geomagnetic storms that brighten auroras and disturb satellites and power grids. Solar flares from reconnection often show a specific timing signature. A burst of high-energy, or hard, X-rays comes first, followed by a slower rise and fade in lower-energy, or soft, X-rays.

That signature is called the Neupert effect, first observed on the Sun in 1968. In simple terms, the hard X-rays track how fast the soft X-rays are building up, because fast electrons from reconnection first slam into dense gas, then heat it.

A Flare Pattern First Seen on the Sun in 1968

Black holes also have coronas — hot, magnetized gas close to the event horizon that shines brightly in X-rays. Scientists have long suspected magnetic reconnection powers some of their flares, but direct evidence has been elusive.

In NGC 3783, the hard X-rays led the soft X-rays by roughly 30,000 seconds, a little over eight hours, and the hard X-ray signal closely tracked the rate of change in soft X-rays. The authors wrote that this pattern "shows that the flare is powered by magnetic reconnection," according to the paper's preprint. The match was strong in data from both XRISM and the European Space Agency's XMM-Newton telescope.

Ultraviolet light from the region lagged the hard X-rays by about 60,000 seconds, consistent with energy spreading outward after the initial burst. On the Sun, the Neupert effect shows up in roughly half of flares, according to studies the authors cite.

At the same time, the team detected an ultra-fast outflow moving at about 20 percent of the speed of light. The authors propose that this outflow plays the role a CME does on the Sun, carrying material away after the magnetic eruption.

Inside NGC 3783's 10-Day Watch

The study was led by Technion doctoral student Gal Vardi and Professor Ehud Behar, with co-authors in Japan, Europe and the United States. The observations came from a 10-day campaign in July 2024 led by XRISM, a joint mission of JAXA, NASA and ESA, with support from XMM-Newton, Chandra, NuSTAR, Swift and NICER. The flare analyzed in the study lasted roughly a day or two, with reconnection-powered emission continuing for about 100,000 seconds.

XRISM is often praised for its high-resolution X-ray spectrometer, but this timing analysis relied mainly on its Xtend imaging camera together with XMM-Newton. The value came from watching how brightness at different X-ray energies changed over time, rather than from fine spectral detail alone.

From the energy involved, the authors estimate the magnetic field in the flaring region exceeded about 13,000 gauss. For comparison, a refrigerator magnet is roughly 100 gauss. The flaring loops sat within about 30 gravitational radii of the black hole, very close in astronomical terms.

One Flare, Several Caveats

The study's own limits are clear. The conclusion rests on a single flare, and the authors say it is uncertain whether the magnetic field strength, loop size, and energies are typical. Their magnetic field estimates span a wide range depending on the method used, and some measurements are upper limits.

The Technion summary describes the work as presenting evidence for magnetic eruptions, which is more cautious than saying the case is settled. Black hole flares are also far more luminous than solar flares, and effects such as relativistic beaming could complicate comparisons.

Readers should also note there is no connection to Earth's space weather — none at all. NGC 3783 is a distant galaxy, and its eruptions pose no risk to us. The interest is in the physics: the same rules that govern the Sun's storms may help explain how black holes flare and drive winds that shape their host galaxies. Astronomers plan to search for the Neupert effect in other active galaxies to see whether this event is common.

The authors suggest the pattern may be hard to spot in many black holes. Flares can be short, overlapping reconnection events can blur the signal, and the geometry of the gas near the black hole may hide the timing. That could explain why it took a long, multi-telescope campaign to catch it once.

What Readers Want to Know

What did XRISM find? A flare near the black hole in NGC 3783 followed the Neupert effect, a timing pattern seen in solar flares, plus a fast outflow likened to a CME.

Is this the first time? The team reports it is the first detection of the Neupert effect around a black hole.

How big is the black hole? About 28 million times the Sun's mass.

Did XRISM's spectrometer make the detection? The timing analysis relied mainly on XRISM's Xtend camera and XMM-Newton.

Does this affect Earth? No. NGC 3783 is a distant galaxy.

Is the finding certain? It is based on one flare, and the authors note several uncertainties.