Within days, astronomers around the world turned their telescopes toward the flash, observing it in X-ray, radio, and other wavelengths.

The tremendous brightness of the flash led astronomers to conclude that it must have been caused by a star being torn apart.

To spot dramatic transient events like these, astronomers need telescopes that continually scan as much of the sky as possible and which flag any sudden changes in brightness — like the Zwicky Transient Facility.

The group flagged this flash to the international community, encouraging researchers who worked using telescopes operating in other wavelengths like radio or X-ray to observe it, too.

As the star is pulled apart and its material is pulled in toward the black hole, the energy of this matter is converted into light.

This both tells astronomers something about the environment around the black hole — that it is not that dense because it allowed optical light to pass through — and shows that looking in the optical range could be a useful way to spot these extreme events in the future.

The need for telescopes to respond quickly to such events is also creating an impetus for greater flexibility in telescope design and planning.

But there’s also a need for telescopes that can respond to rare events within hours or even minutes.

But recently built ground-based telescopes, like the MASTER network or the GROWTH-India telescope, specialize in scanning the sky for gamma-ray events and immediately and autonomously moving to observe them

There’s increasing interest in considering how telescopes can respond to these brief and rare but scientifically important events

Both the international cooperation between researchers working with different telescopes and the ability of those telescopes to respond rapidly were essential for making this breakthrough in black hole observations, Andreoni said