A galaxy located about 10 billion light-years away has dimmed dramatically, losing 95% of its brightness in just 20 years. Researchers from the Chiba Institute of Technology believe a supermassive black hole is running low on fuel, changing the way we think about black hole behavior.
Traditionally, scientists believed that changes in black holes occurred over thousands of years, far beyond human observation capabilities. However, the galaxy known as J0218−0036 has shown noticeable changes within a single researcher’s career.
Published on November 4, 2025, in the Publications of the Astronomical Society of Japan, the study used historical data and new observations from powerful telescopes.
A Closer Look: Comparing Snapshots
Researchers analyzed about 31,500 quasars, using data from the Sloan Digital Sky Survey (SDSS) from around 2002 and newer images from the Hyper Suprime-Cam (HSC) taken in 2018. When they focused on J0218−0036, the difference was striking—the galaxy had faded significantly across all measured wavelengths.
Typically, active galactic nuclei, which are bright cores powered by black holes, vary in brightness by about 30%. In this case, they found a 20-fold decrease in brightness, indicating one of the largest changes ever recorded for such objects.
Ruling Out Simpler Explanations
Initially, researchers considered the possibility that dust might be blocking the light from the galaxy. This can happen and would have provided a less dramatic explanation. However, multi-wavelength analysis ruled out this scenario. The data suggested that the black hole’s core was losing brightness rather than being obstructed by dust.
By applying statistical tools like the Akaike Information Criterion, the researchers confirmed that the black hole was indeed starving for material.
Implications for Black Hole Science
This discovery could change how scientists understand black hole behavior. Traditionally, changes in accretion rates—the rate at which black holes consume surrounding gas—were believed to take tens of thousands of years. However, for J0218−0036, the observed timescale for these changes was only about 2,000 days.
Lead researcher Tomoki Morokuma expressed excitement over this short timescale, stating, “It is fascinating that an active galactic nucleus can change its brightness so dramatically over such a short period.” Co-author Toshihiro Kawaguchi emphasized that these rapid changes challenge existing models, suggesting that a new understanding of black hole mechanics may be necessary.
The Bigger Picture
This research highlights a breakthrough in our understanding of supermassive black holes. According to a 2022 survey, only about 5% of galaxies show significant activity, making J0218−0036 a rare and valuable case for future studies. As scientists continue to gather data, we might learn more about how these cosmic giants behave over time.
For anyone interested in the mysteries of the universe, this discovery serves as a reminder of how much we still have to learn. Understanding black holes like J0218−0036 could offer new insights into the evolution of galaxies and our place within the cosmos.
For more detailed findings, you can read the complete study here.
