After searching for planets around other stars for hundreds of years, astronomers confirmed the first one in 1992. Very surprisingly, this planet orbited a neutron star rather than a Sun-like star. In the salamander scenario (so called because the planet would have passed through the fire of the supernova explosion), this planet was formed at the same time as its host stars formed, an analogous situation to our own solar system. A second hypothesis — considered more likely — was that the planet would have been formed out of the debris of the supernova explosion, independent of any possible exoplanets orbiting during the star’s main sequence lifetime. Since the 1990s, thousands of exoplanets have been discovered, allowing us to compare the properties of the planet orbiting the neutron stars to the planets currently orbiting stars that will become neutron stars later in their evolution. To that end, we combed NASA’s Exoplanet Archive and the NASA Astrophysics Data System for hot and massive stars that are known to host planets. We then compare the properties of those planets to the properties of that first planet discovered.
