An emitting star, also known as a pulsar, is a type of neutron star that emits a beam of electromagnetic radiation. It is formed when a massive star collapses and its core is compressed into an incredibly dense object. The radiation is emitted in a lighthouse-like fashion, with the beam sweeping across the sky as the star rotates. Pulsars are some of the most energetic objects in the universe and can be used to study the physics of extreme gravity and matter.