Could primordial black holes be dark matter?: “A small, primordial black hole would be the size of an atom but have the mass of an asteroid,” he points out. “Its strong gravitational field, as it cut through the sun, would squeeze it, then release, and cause the sun to oscillate before ultimately settling down.”
The idea is to measure the oscillation, and determine what would cause it. “Shravan Hanasoge wrote a program to help us with a simulation to see what the sun would look like if a primordial black hole passed through. The smallest mass detectable is 10^21 grams,” Kesden continues.