As­tronomers found stars careening around these centers, zooming at previously unheard-of speeds in their orbits. The motion was like an accelerating ice skater pulled around her partner in a tight twirl – or like a fish caught in a superstrong whirlpool. Something ex­treme had to be in the middle of each of those galaxies. You might be able to guess what this was, but for scientists, the best answer came as a shock. In 1994 telescopic evidence confirmed the amazing cause: a supermassive black hole, with the mass not of one imploded star, not of two, but of millions – maybe even billions.

—A Black Hole Is NOT a Hole,
Carolyn Cinami DeCristofano

Which connection helps the reader understand how supermassive black holes were found?

careening stars and orbits
astronomers and telescopic evidence
fish and whirlpools