A black hole collision created a bright flash of light
In 2020, scientists studying gravitational waves discovered a black hole with an end streak of light. This was the first time a black hole would let anything escape its path. It was identified that two galactic behemoths, two crushed clouds of gas, collided.
In simple terms, two massive black holes collided, causing a crush of individual gasses, which resulted in a bright flare following at the end like a tail. This rather massive event occurred in a galaxy distant from us, approximately 4.6 billion light-years from Earth.