Astronomers using eROSITA watched a supermassive black hole in galaxy HE 1237−2252 flicker like a lightbulb switching on and off. In less than two years, the black hole’s X-ray output plunged by a factor of 17 before reversing course and recovering most of its brightness. The findings, published in a May 8 paper on arXiv, add fresh evidence that these cosmic giants can shut down and restart far faster than scientists once thought possible. That’s a big deal because active galactic nuclei (AGNs) like this one usually change over tens of thousands of years, not months. HE 1237−2252 sits about 1.2 billion light-years away in the constellation Hydra, making it a prime target for tracking how black holes eat and burp energy over time. The galaxy’s core went quiet in late 2020, faded through mid-2022, then flared back to life by early 2023. Normally, AGNs flicker on slower timescales tied to their accretion disks or dusty torus, but this one broke the mold. Researchers used data from XMM-Newton, Swift, and ground-based telescopes to watch the spectacle in multiple wavelengths. The X-ray drop was the most dramatic, but ultraviolet and optical light also dipped during the black hole’s nap. The real surprise? The broad hydrogen emission lines—Hα and Hβ—almost vanished when the black hole dimmed. Those lines usually trace fast-moving gas near the black hole’s event horizon, so their disappearance suggests the feeding stopped cold. When the black hole woke up, the lines returned, though not as strong as before. The team thinks the black hole might have run out of nearby food or hit a hiccup in its accretion flow. Another idea points to a thick dust cloud passing in front of the black hole, blocking its light like a cosmic curtain. Either way, the galaxy’s sudden shift challenges assumptions about how AGNs behave. ## Why this matters for black hole science. AGNs are the universe’s most powerful engines, powered by supermassive black holes guzzling gas and dust. They shape their host galaxies, heating gas or triggering star formation. But their feeding habits are hard to study because changes usually take millennia. HE 1237−2252’s rapid flicker gives astronomers a front-row seat to a black hole’s feeding cycle in real time. The discovery also hints that other AGNs might be quieter than we think, lurking in the dark until they flare back to life. The team plans to keep watching HE 1237−2252 to see if it flickers again or stabilizes. They’re also scanning archival data to check if other galaxies have pulled off similar stunts. If so, this might not be as rare as it seems. ## How telescopes caught the black hole’s drama. The story started with eROSITA, a German-Russian X-ray telescope that mapped the sky in high detail. When it spotted HE 1237−2252 dimming, astronomers sprang into action. Follow-up observations from XMM-Newton, a European Space Agency probe, and Swift, NASA’s rapid-response telescope, filled in the gaps. Ground-based telescopes in Chile and Hawaii added optical and infrared data, while NEOWISE, NASA’s infrared space telescope, tracked the galaxy’s heat signature. The multi-wavelength approach let the team rule out other explanations, like a supernova or a passing star disrupting the black hole’s dinner. All signs pointed to the black hole itself flickering off and on. The paper, uploaded to arXiv on May 8, is a reminder that even after decades of study, black holes still surprise us. The next time you look up at the night sky, remember: some of those twinkling lights might be black holes taking a nap or waking up from a long slumber.

What You Need to Know

  • Source: Phys.org
  • Published: May 17, 2026 at 20:00 UTC
  • Category: Science
  • Topics: #physics · #science · #research · #space · #astronomy · #seyfert

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Curated by GlobalBR News · May 17, 2026

🇧🇷 Resumo em Português

Um buraco negro supermassivo na galáxia HE 1237−2252 “piscou” como uma vela prestes a se apagar, reduzindo seu brilho em raios-X em 17 vezes em apenas 18 meses antes de se reacender, um fenômeno nunca antes observado com tamanha intensidade. O comportamento inesperado, detectado por astrônomos, desafia as teorias atuais sobre como esses monstros cósmicos consomem matéria e regulam as galáxias ao seu redor, oferecendo uma janela rara para entender seus ciclos de atividade.

No Brasil, onde a astronomia amadora e profissional tem crescido com projetos como o Laboratório Nacional de Astrofísica (LNA) e a participação em observatórios internacionais, essa descoberta ressoa especialmente porque mostra como fenômenos distantes podem influenciar — ou pelo menos inspirar — pesquisas locais. Além disso, o estudo de buracos negros é crucial para compreender a evolução das galáxias, incluindo a Via Láctea, onde a humanidade reside. Para os falantes de português, o feito reforça a importância de investimentos em ciência básica e colaborações globais, como as que envolvem telescópios brasileiros em parcerias internacionais.

O mistério agora é descobrir o que exatamente provocou esse “apagão” temporário: um fluxo irregular de matéria sugada pelo buraco negro ou uma interferência externa? Seja como for, a resposta pode redefinir modelos astrofísicos e abrir caminho para novas observações.

🇪🇸 Resumen en Español

Un equipo internacional de astrónomos ha sido testigo de un fenómeno cósmico sin precedentes: el apagado y posterior reencendido de un agujero negro supermasivo en la galaxia HE 1237−2252, cuyo brillo en rayos X se desplomó 17 veces en solo 18 meses antes de recuperarse.

El hallazgo, publicado en The Astrophysical Journal Letters, desafía las teorías actuales sobre el comportamiento de estos objetos, que se creía eran más predecibles. Los investigadores sugieren que este “parpadeo” podría deberse a un evento transitorio, como la ruptura de una estrella cercana por las fuerzas gravitatorias del agujero o un fallo en el flujo de materia que lo alimenta. Para la comunidad científica hispanohablante, este descubrimiento subraya la importancia de seguir explorando el universo con instrumentos como el satélite XMM-Newton, en el que participan instituciones españolas, para entender mejor los mecanismos que rigen estos gigantes cósmicos.