When we gaze at the night sky, we often think about the incredible phenomena that occur beyond our planet. One of the most powerful and mysterious cosmic events are gamma-ray bursts, which can occur through two primary mechanisms: the cataclysmic merger of neutron stars or the dramatic collapse of a massive star. In these violent scenarios, a black hole is born, unleashing jets of energy that travel at almost the speed of light. Imagine witnessing one of these jets aimed directly at Earth; thanks to a phenomenon called Doppler boosting, we can observe these extraordinary displays from distances reaching billions of light-years. Over the past ten years, astronomers have detected thousands of gamma-ray bursts, expanding our understanding of these cosmic fireworks.
Launched in 2024, the Einstein Probe—a state-of-the-art X-ray space telescope created through a collaboration between the Chinese Academy of Sciences (CAS), the European Space Agency (ESA), and the Max Planck Institute for Extraterrestrial Physics—has been busy scanning the cosmos for these energetic explosions. In April, the Einstein Probe recorded a unique event labeled EP240408A. An international team of astronomers, including Dheeraj Pasham from MIT, Igor Andreoni from the University of North Carolina at Chapel Hill, and Brendan O’Connor from Carnegie Mellon University, have conducted extensive investigations into this event, utilizing various ground-based and space-based telescopes such as NuSTAR, Swift, Gemini, Keck, DECam, VLA, ATCA, and NICER, which was developed in collaboration with MIT.
The findings from their research, detailed in a recent report published in The Astrophysical Journal Letters, reveal that the characteristics of EP240408A diverge significantly from those of classic gamma-ray bursts. Instead, it may belong to an elusive category of cosmic explosions called jetted tidal disruption events, occurring when a supermassive black hole disrupts a star.
“The versatility of NICER in monitoring different sections of the sky for extended periods has been crucial for our comprehension of such extraordinary cosmic explosions,” Pasham, a research scientist at the MIT Kavli Institute for Astrophysics and Space Research, notes.
While the idea of a jetted tidal disruption event seems plausible, its unique traits pose intriguing questions for the researchers. O’Connor reflects, “EP240408A meets some criteria for various cosmic phenomena but doesn’t align perfectly with any. Its brief duration and exceptionally high luminosity present challenges for other explanations. Perhaps we’re witnessing something entirely unprecedented!”
Pasham surmises that the Einstein Probe is just beginning to explore the astonishing possibilities that lie ahead. “I am eager to uncover the next strange explosion detected by the Einstein Probe,” he expresses, capturing the shared enthusiasm of astronomers worldwide as they look forward to discovering more extraordinary explosions from the farthest corners of the universe.
Photo credit & article inspired by: Massachusetts Institute of Technology
