A Neutron Star Is Born

A neutron star was first detected as a pulsar in 1967. It is one of the most mysterious compact objects universe, with radius order 10 km and masses that can reach two solar masses. In fact, stars are remnants, kind stellar zombies (they die, but do not disappear). last decades, astronomical observations yielded various contraints for finally, 2017, gravitational wave (GW170817). Its source identified merger coming from NGC 4993, galaxy 140 million light years away us. The very same event $\gamma$-ray, x-ray, UV, IR, radio frequency even optical region electromagnetic spectrum, starting new era multi-messenger astronomy. To understand describe stars, an appropriate equation state satisfies bulk nuclear matter properties necessary. GW170817 detection contributed extra constraints to determine it. On other hand, magnetars sort objects, bearing much stronger magnetic fields up 10$^{15}$ G on surface compared usual 10$^{12}$ present ordinary pulsars. While description pulsars completely established, describing poses challenges. this paper, I give overview history development models show how tiny world physics help understanding cosmos, especially stars.