Enter a clue or pattern or both:
The Clue
Stars that exhibit the "lighthouse effect" (7 letter answer)
The Answer
PULSARS
Tags
Notes
The answer PULSARS is so rare that it appears less than once every 2500 puzzles.
Definition
PULSAR as a noun:
1. a degenerate neutron star; small and extremely dense; rotates very fast and emits regular pulses of polarized radiation