The origin of the planet orbiting PSR1829 – 10

Abstract

BAILES et al.¹ have reported the discovery of a planet-mass object in a six-month orbit around the radio pulsar PS R1829–10. The parameters of the orbit, in particular its circularity, make it unlikely that this planet existed before the supernova explosion that presumably created the pulsar, and somehow survived¹. Here we present two alternative explanations for the existence and orbital parameters of the claimed planet-mass object. In the first, the pulsar forms from the coalescence of two white dwarfs, and the planet condenses from a massive disk of material left behind. In the second, a neutron star collides with and cannibalizes the central star of a solar-type planetary system. The orbits of the inner planets are made elliptical by this collision, but then recircularized by drag forces due to the extended but short-lived envelope of the disrupted central star.