You're thinking of pulsars, which are rotating neutron stars that emit directional beams of radio waves.

Here's how it works:

* Neutron stars: These are incredibly dense, collapsed cores of massive stars that have exploded as supernovae.

* Rotation: Neutron stars rotate incredibly fast, some completing a rotation in milliseconds.

* Magnetic field: They have incredibly strong magnetic fields, billions of times stronger than Earth's.

* Radio beams: These strong magnetic fields accelerate charged particles, generating powerful beams of radio waves that shoot out from the magnetic poles.

* Pulsars: Because of their rotation, these beams sweep across space like a lighthouse beam, appearing as regular pulses of radio waves to observers on Earth.

So, the answer is: Yes, rotating stars that emit directional beams of radio waves are called pulsars.