Astronomers have found a small star (a pulsar called PSR J1824-2452I) undergoing a radical transformations.
The pulsar’s tiny companion star is pounding it with streams of matter. This lights up the pulsar in X-rays, making it spin faster and faster until it becomes a “millisecond pulsar” that spins at hundreds of times a second and emits radio waves.
Normally the pulsar’s magnetic field shields itself from this onslaught. But sometimes, the streams overwhelm the pulsar’s protective “force field”. Eventually the streams slacken and the pulsar’s magnetic field is able to fend off the attacks.
Right now, the pulsar alternates between emitting millisecond X-ray pulses when the companion is flooding the pulsar with matter, and extremely fast radio pulses when it is not, all in just a matter of weeks.Read more at CSIRO