Craig O. Heinke

The binary star KL Dra works like a neon clock: every two months it lights up for a few days, and between these outbursts it blinks with short but bright pulses. For eleven straight years, telescopes have kept their eyes on it, and now the whole mechanism is visible.

Terzan 5 is a globular star cluster, a tight swarm of hundreds of thousands of stars squeezed into a sphere a few dozen light-years across. In such a crowd, stars exchange matter and spin each other up, and some turn into pulsars — rapidly rotating neutron stars that emit radio pulses like lighthouses. New images taken with the Karl G.