Small, hardy planets most likely to survive death of their stars

14 May 2019 03:33 PM

Small, hardy planets packed with dense elements have the best chance of avoiding being crushed and swallowed up when their host star dies, new research from the University of Warwick has found.

Supported by STFC the astrophysicists from the Warwick Astronomy and Astrophysics Group modelled the chances of different planets being destroyed by tidal forces when their host stars become white dwarfs and they have determined the most significant factors that decide whether they avoid destruction.

Their ‘survival guide’ for exoplanets could help guide astronomers to locate potential exoplanets around white dwarf stars, as a new generation of ever more powerful telescopes are being developed to search for them.

By modelling the effects of a white dwarf’s change in gravity on orbiting rocky bodies, the researchers have determined the most likely factors that will cause a planet to move within the star’s ‘destruction radius’; the distance from the star where an object held together only by its own gravity will disintegrate due to tidal forces. Within the destruction radius a disc of debris from destroyed planets will form.

Although a planet's survival is dependent on many factors, the models reveal that the more massive the planet, the more likely that it will be destroyed through tidal interactions. 

You can read more about this research here