Astronomers were able to capture the moment when a supermassive black hole in a galaxy 215 million light-years away tore apart a bright star.
The so-called “tidal disturbance event” (TDE) is the closest death to a star humanity has ever seen.
Astronomers were alerted by the flash of intense light, visible hundreds of millions of light-years away, before parts of the star disappeared on the black hole’s event horizon after the massive gravitational “dance”.
TDE, called AT2019qiz, was spotted in September 2019, and was discovered by astronomer Matt Nicole of the University of Birmingham and his team over the next six months.
Such stellar events are almost impossible to predict, and are only seen through constant observation of the sky, along with good luck. And precisely when the colossal flare erupted during TDE, astronomers responded with dizzying speed, pointing to a wide range of telescopes in the constellation Eridanus.
“We immediately directed a group of ground and space telescopes in this direction to find out how to produce light,” said astronomer Thomas Weavers, who was based at Cambridge University during the research.
The European Southern Observatory’s Very Large Telescope, the new technology telescope, the global telescope network of the Las Compres Observatory, and the Neil Gehrels Swift satellite participated in monitoring the event, providing data on multiple wavelengths of light, including ultraviolet, radio and X-rays.
And since TDEs mostly glow in light and ultraviolet rays, it was fortunate that all of these resources could be combined and directed very quickly to capture such a rare event.
The glow itself is the result of the nearly inexplicable forces of gravity and friction within the filaments of the cosmic event, which consist of matter from the star. At certain points, the TDE event eclipses its host galaxy for some time before slowly fading away over time until nothing remains.
Based on their observations, the researchers determined that the star was at some point roughly the same mass as our sun, and lost half of its mass to the black hole.
TDE’s observations finally provided direct evidence of the outflow of gas during these events, which has long been theorized and debated, but has never been observed. In fact, researchers now know, at least in this case, that the black hole released powerful jets of dust outward at speeds of up to 10,000 km / s as it devoured the star.
This explains the earlier light and radio emissions that astronomers, who study black holes over the years, have been left somewhat unexplained and little understood.
“This event teaches us about the detailed physical processes of accumulation and mass ejection from supermassive black holes,” said astronomer Edo Berger of the Harvard-Smithsonian Center for Astrophysics. The researchers described AT2019qiz as a “rational stone for interpreting future TDE observations” ahead of much of the anticipated observations, from elsewhere in the scientific and astronomical community.