Answer:
neutron star
Step-by-step explanation:
A neutron star is formed when a star which had a mass of between 10 and 29 solar masses collapses. They have a radius of about 10 kilometers and a mass of about 1.4 solar masses. When star loses its original mass the rotation speed increases drastically.
This rotation increases the electromagnetic field generated by the star which exits from the magnetic poles of the star. When there is misalignment of the stars rotational and magnetic axis the electromagnetic radiation is released once every rotation. This causes the EM radiation to be emitted in pulses.