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takyon [soylentnews.org] writes:

Despite the harsh radiation released by pulsars [wikipedia.org], exoplanets orbiting them may be "habitable" [discovermagazine.com] if their atmospheres are thick enough:

The most exciting exoplanet finds are those that orbit within their host star's habitable zone, an area at just the right distance from the star to allow for liquid surface water and thus, potentially life. The paper's authors, two astronomers at Leiden Observatory in the Netherlands, suggest that pulsars have their own habitable zones — surprising, given the harsh X-rays and other radiation [nasa.gov] that such stars emit.

But, if a planet is big enough — some one to 10 times Earth's mass — and it has an atmosphere at least 1 million times as thick as Earth's, then it might just cut it as habitable even around a pulsar. The idea is that the enormous atmosphere would act as a shield for the planet's surface, absorbing the deadly radiation while still allowing for enough heat to melt water. And a bigger world, preferably with a decent magnetic field, is necessary to hold on to that atmosphere over long enough time scales.

It doesn't sound like complex life would make the cut.

Neutron star planets: Atmospheric processes and irradiation [aanda.org] (open, DOI: 10.1051/0004-6361/201731102) (DX [doi.org])

Of the roughly 3000 neutron stars known, only a handful have sub-stellar companions. The most famous of these are the low-mass planets around the millisecond pulsar B1257+12. New evidence indicates that observational biases could still hide a wide variety of planetary systems around most neutron stars. We consider the environment and physical processes relevant to neutron star planets, in particular the effect of X-ray irradiation and the relativistic pulsar wind on the planetary atmosphere. We discuss the survival time of planet atmospheres and the planetary surface conditions around different classes of neutron stars, and define a neutron star habitable zone based on the presence of liquid water and retention of an atmosphere. Depending on as-yet poorly constrained aspects of the pulsar wind, both Super-Earths around B1257+12 could lie within its habitable zone.

Original Submission