{"id":2656,"date":"2026-03-27T18:34:25","date_gmt":"2026-03-27T17:34:25","guid":{"rendered":"https:\/\/www.for5195.uni-wuerzburg.de\/?page_id=2656"},"modified":"2026-03-27T19:20:00","modified_gmt":"2026-03-27T18:20:00","slug":"research-unit-scientists-explain-puzzling-difference-in-black-hole-images","status":"publish","type":"page","link":"https:\/\/www.for5195.uni-wuerzburg.de\/index.php\/research-unit-scientists-explain-puzzling-difference-in-black-hole-images\/","title":{"rendered":"Research-Unit Scientists Explain Puzzling Difference in Black-Hole Images"},"content":{"rendered":"\n

January 2026:<\/strong>
New simulations reveal how energetic particles and magnetic eruptions shape the glowing ring around M 87’s black hole.<\/strong><\/p>\n\n\n\n

Researchers at the Chair of Astronomy at the Julius-Maximilians-Universit\u00e4t W\u00fcrzburg have resolved a longstanding puzzle in black hole observations: Why the supermassive black hole in the galaxy M 87 shows different ring sizes at two radio frequencies. Their work combines state-of-the-art 3D supercomputer simulations with the latest observations from two global radio-telescope networks, the Event Horizon Telescope (EHT) and the Global Millimeter VLBI Array (GMVA). These arrays link antennas across the globe, including telescopes in Antarctica and Greenland forming an Earth-sized virtual telescope. The results of this study appeared quite recently in Astronomy & Astrophysics<\/a>.<\/p>\n\n\n\n

\"Location
Location of the telescopes of the EHT (red) and GMVA (orange) as well as planed telescopes of the ngVLA (blue) and the Wetterstein Millimeter Telescope (blue\/white). Shared locations are shown in split colours. Credit: Ainara Saiz-P\u00e9rez and Christian M. Fromm<\/figcaption><\/figure>\n\n\n\n

M 87: A Unique Laboratory<\/strong><\/p>\n\n\n\n

The galaxy M 87, a mere 55 million light-years away, hosts a black hole 6.5 billion times the mass of the Sun. It became iconic in 2019 as the first black hole ever imaged and is known for its powerful jet stretching thousands of light-years. Because M 87 is large, bright and relatively nearby, it offers a rare opportunity to study how black holes feed on surrounding matter and launch jets.<\/p>\n\n\n\n

The black hole itself is invisible, but the superheated plasma swirling around it glows. Gravity bends this light into a bright ring surrounding a darker \u201cshadow\u201d, offering clues about the black hole and the extreme physics near it.<\/p>\n\n\n\n

Why the Ring Appears Different at 230 GHz and 86 GHz<\/strong><\/p>\n\n\n\n

The EHT observed a ring about 42 microarcseconds wide at 230 GHz \u2013 similar to spotting an
orange on the Moon. Later GMVA observations at 86 GHz found a larger ring, about 64
microarcseconds across. The new simulations show that this difference is actually expected:<\/p>\n\n\n\n