James Webb Telescope Measures Most Distant Dormant Black Hole

Astronomers have used the James Webb Space Telescope to measure the mass of a dormant supermassive black hole located in a galaxy approximately 10 billion light-years away. This measurement provides new data on black holes from a period when the universe was much younger.

The research focused on galaxy MRG-M0138, which appears as it was when the universe was around four billion years old. The team determined that the black hole in this galaxy has a mass roughly six billion times greater than that of the Sun.

Gravitational lensing played a key role in enabling these observations. This effect magnified the distant galaxy by about 30 times, allowing astronomers to track the movement of stars near the black hole and estimate its mass.

The measurement represents the most distant dormant black hole whose mass has been directly determined so far. Dormant, or inactive, black holes do not emit detectable radiation, making them challenging to study without advanced techniques.

What the numbers show

• The black hole is located about 10 billion light-years from Earth
• Its mass is estimated at six billion solar masses
• The findings were published on June 4, 2026

The study was led by Yonsei University and included an international research team with participation from Professor Ji Myung-Kuk. Seven separate gravitational lens models were used to confirm the reliability of the mass measurement.

Researchers stated that this work enables a more comprehensive understanding of black hole development over cosmic time. The findings also contribute to knowledge about the role of black holes in the evolution of galaxies.

The discovery was published in the journal Science, making the details available to the scientific community for further analysis. The results highlight the capabilities of the James Webb Space Telescope in exploring distant and difficult-to-observe astronomical objects.

* This article is based on publicly available information at the time of writing.