Four years ago, astronomers made an incredible discovery: a supermassive black hole was consuming an entire star. The star came too close, and the black hole’s gravity was too strong to resist. This cosmic event is known as a tidal disruption event (TDE), and it’s still fascinating scientists today.
This particular TDE is called AT2018hyz. The name breaks down as follows: “AT” stands for Astronomical Transient, “2018” is the year it was first spotted, and “hyz” is just part of its designation. The event was initially detected by a survey for supernovae in 2018, but the radio emissions that followed weren’t observed until 2022.
A new study published in The Astrophysical Journal reveals that the energy output from AT2018hyz is still climbing. Yvette Cendes, an Assistant Professor at the University of Oregon, led the research. She and her team have tracked this TDE for years, reporting that the emissions have increased dramatically since the event.
The researchers found that the energy emitted now is about 50 times greater than what was first recorded. Cendes explains that there are two likely scenarios for this rising luminosity. One possibility is a “delayed spherical outflow” that started about 620 days after the star was consumed. This means the outflow of energy didn’t happen immediately but took time to develop.
The second scenario involves an astrophysical jet, which could be moving at near-light speed. Such jets often appear weaker initially but gain strength over time as they spread out.
The implications of this research are vast. Cendes remarked, “This is really unusual. I’d be hard-pressed to think of anything rising like this over such a long period of time.” The current energy output of the black hole rivals that of gamma-ray bursts, some of the universe’s most powerful explosions.
For a bit of fun, the authors even compared the energy output of the black hole to the fictional Death Star from Star Wars. They calculated that this black hole might be emitting over one trillion times more energy than the Death Star.
What’s intriguing is that this isn’t the only black hole experiencing delayed emissions. Other tidal disruption events may share this characteristic, but AT2018hyz stands out for its extreme brightness. This raises a bigger question: Are there other black holes exhibiting similar behavior? We don’t know yet because researchers haven’t thoroughly examined them.
Cendes highlights the challenge: “If you have an explosion, why would you expect to see something years later when you didn’t see anything before?” Moreover, accessing time on the most powerful telescopes for observation is a competitive endeavor. However, now that one bright black hole has been identified, future searches may gain momentum.
The study of AT2018hyz is unique within the realm of tidal disruption events, and its ongoing monitoring may help scientists understand deeper cosmic phenomena. Cendes and her team intend to continue their observations across various frequencies, allowing for a better grasp of the events shaping our universe.
For more information on tidal disruption events and their significance, you can read more from Universe Today here.
