Formation PSR B1257+12 C

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when psr b1257+12 c , neighbors discovered, scientists puzzled on how planets formed. normally, planets orbiting around massive star evaporate when host star exploded in supernova due intense heat (up 1,000,000 k) , radiation. discovery of planets around pulsar unexpected, considering pulsar host planetary companions.


several theories have been proposed how planets around psr b1257+12 formed. 1 theory suggested planets had existed before host star exploded in supernova 1 billion years ago, however, inconsistent ejected material supernova enough vaporize planets close star. also, multiple issues arise theory debates nearly-impossible steps on how planets ended in current places. thus, scenario has been dropped.


one scenario proposed massive binary system in planets formed around, more massive companion exploding in supernova. neutron star orbit secondary companion (forming x-ray binary) until now-red supergiant exceeded roche lobe , began spilling material onto neutron star, transfer being dramatic forms thorne–Żytkow object. doesn t explain how pulsar reach spin rate of 6 milliseconds, model still being questioned.


another model stated planets might have formed fallback disk supernova remnant. main problem resulting pulsar radio pulsar, not kind of pulsar psr b1257+12 is. thus, unlikely how formed.


the accepted model planets around psr b1257+12 result of 2 white dwarfs merging. white dwarfs in binary orbit, orbit decaying until lighter white dwarf star filled roche lobe. if mass ratio large, lighter companion disrupted, forming disk around more massive companion. star accrete material, , result in mass increasing until reaches chandrasekhar limit, in experience core collapse , turn rapidly rotating neutron star, or, precise, pulsar. after explosion, disk around pulsar still massive enough (about 0.1 m☉) form planets, terrestrial, due them being composed of white dwarf material such carbon , oxygen.








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