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Space and PhysicsAstronomy

The Deadliest Stars In The Universe Could Support Habitable Planets

author

Jonathan O'Callaghan

Senior Staff Writer

clockDec 20 2017, 17:45 UTC

Artist's impression of a habitable pulsar planet. Institute of Astronomy, University of Cambridge

Pulsars are some of the most violent stars in the universe, firing out bursts of radiation capable of sterilizing a planet. But a study has claimed that it might be possible for habitable planets to orbit these dangerous stars.

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Published in the journal Astronomy and Astrophysics, two scientists from Leiden University in the Netherlands studied the pulsar PSR B1257+12, located 2,300 light-years from Earth, with the Chandra space telescope. Of the five known pulsar planets, three orbit this pulsar, and they were the first exoplanets ever found more than two decades ago.

Pulsars are rapidly rotating neutron stars, the remaining cores of larger stars after they go supernova. They can rotate at up to several thousand times per second, and as such blast out deadly gamma rays and X-rays, among other particles.

These conditions certainly don’t look hospitable to life as we know it. However, this new study claims that these stars – containing the mass of our Sun squashed into the size of a city – may have a habitable zone at a similar distance to Earth's orbit around the Sun, where planets could host liquid water.

"According to our calculations, the temperature of the planets might be suitable for the presence of liquid water on their surface,” lead author Alessandro Patruno said in a statement.

Are pulsars as deadly as we thought? NASA’s Goddard Space Flight Center

There are some prerequisites, though. The planets would have to be super-Earths, about four to five times more massive than our planet. They would also need to have extremely thick atmospheres, in order to withstand the barrage of radiation from their pulsar.

Two of the three known planets around PSR B1257+12 are super-Earths. It’s not known if they have the right atmospheres to support life, but it seems there is a surprising possibility. As pulsars emit no visible light, any life here would likely be very different to our planet.

"The two Super-Earths may have retained their atmosphere for at least a hundred million years provided they contain a large atmospheric fraction of the total planet mass," the authors write in their paper.

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Conditions on these worlds would be inhospitable to humans, with the atmospheric pressure from such thick atmospheres being similar to the bottom of Earth’s oceans. But we know some forms of life can survive here, so perhaps it can also survive on pulsar planets.

These planets also have the potential to be water-rich. Any planets that formed from the disc of debris from the supernova could have access to an abundance of oxygen. If they’re in the habitable zone, temperatures could be just right for liquid water.

"At the moment there is no way to directly see the atmospheres of these two super-Earth planets," Patruno told IFLScience. "However, there might be some indirect methods to determine whether they do have indeed a thick atmosphere. One possibility would be to use the X-rays coming from the pulsar."

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There are an estimated 1 million neutron stars in our galaxy, 200,000 of which are pulsars. Perhaps worlds orbiting these seemingly inhospitable stars will be intriguing targets to search for life.


Space and PhysicsAstronomy
  • exoplanet,

  • telescope,

  • Astronomy,

  • search for life,

  • habitable planet,

  • pulsar planet