Astronomers have discovered that a Sun-like star 550 light years from Earth is slowly consuming its “offspring” – crushing one or more planets in its orbit into vast clouds of gas and dust. The distant star called RZ Picseum located in the constellation Pisces – is an insatiable “eater of worlds”. The discovery, published in the Astronomical Journal, may shed light on a brief but volatile period in the history of many solar systems, including our own. “We know it’s not uncommon for planets to migrate inward in young solar systems since we’ve found so many solar systems with ‘hot Jupiters’ – gaseous planets similar in size to Jupiter but orbiting very close to their stars,” said Catherine Pilachowski, from the Indiana University in the US.
“This is a very interesting phase in the evolution of planetary systems, and we’re lucky to catch a solar system in the middle of the process since it happens so quickly compared to the lifetimes of stars,” Pilachowski said. Doomed worlds that fly too close to their sun – only to be ripped apart by its tidal forces – are officially known as “disrupted planets.” In the case of RZ Piscium, the material near the sun-like star is being slowly pulled apart to create a small circle of debris about the same distance from the star as the planet Mercury’s orbit is from our sun. “Based on our observations, it seems either that we’re seeing a fairly massive, gaseous planet being pulled apart by the star, or perhaps two gas-rich planets that have collided and been torn apart,” Pilachowski said.
Even solar systems whose planets are not lost to their sun are unstable in their early history, since newly born planets interact strongly with one another – as well as their sun – through gravity, she said. “This discovery really gives us a rare and beautiful glimpse into what happens to many newly formed planets that don’t survive the early dynamical chaos of young solar systems,” Pilachowski said. “It helps us understand why some young solar systems survive – and some don’t,” she added.