Scientists find a planet-eating 'Death Star' which is just like the Earth's Sun

In a rare discovery, scientists have discovered a planetary system with a host star or death star which may have eaten up some of its planets. The death star is similar to Earth’s Sun.

Jacob Bean, assistant professor at the University of Chicago in the US said that this doesn’t mean that Earth could be eaten up by the Sun in future.

“It doesn’t mean that the Sun will ‘eat’ the Earth any time soon,” said Jacob Bean, assistant professor at the University of Chicago in the US.

He however said that this discovery is an indication that planetary systems, including our own, may have commonly witnessed violent histories.

“But our discovery provides an indication that violent histories may be common for planetary systems, including our own,” said Bean.

Researchers said that this natural version could provide clues about how planetary systems evolve over time, unlike the artificial planet-destroying Death Star in the movie “Star Wars.”

In 1995, the scientists had discovered the first planet orbiting a star other than the Sun. More than 2,000 exoplanets have been identified since then.

Rare are those planets that orbit a star similar to the Sun. Their extreme similarity to the Sun make these so-called solar twins ideal targets for investigating the connections between stars and their planets.

Star named HIP68468, which is 300 light years away, was studied by Bean and his colleagues, as part of their multi-year project to discover planets that orbit solar twins.

Megan Bedell, a UChicago doctoral student said that it is tricky to draw conclusions from a single system.

Debra Fischer, a professor of astronomy at Yale University who was not involved in the research said that Computer simulations show that billions of years from now the accumulated gravitational tugs and pulls between planets will eventually cause Mercury to fall into the sun.

“This study of HIP68468 is a post-mortem of this process happening around another star similar to our Sun. The discovery deepens our understanding of the evolution of planetary systems,” said Fischer.

In 2015, the research team discovered its first exoplanet using the 3.6-metre telescope at La Silla Observatory in Chile.

The more recent discovery needs to be confirmed, but includes two planet candidates - a super Neptune and a super Earth.

Their orbits are surprisingly close to their host star, with one 50 per cent more massive than Neptune and located at a Venus-like distance from its star, researchers said.

The other, the first super Earth around a solar twin, is three times the Earth’s mass and so close to its star that its orbit takes just three days, they said.

“These two planets most likely didn’t form where we see them today,” Bedell said.

Instead, they probably migrated inward from the outer parts of the planetary system. Other planets could have been ejected from the system - or ingested by their host star.

HIP68468’s composition points to a history of ingesting planets. It contains four times more lithium than would be expected for a star that is 6 billion years old, as well as a surplus of refractory elements - metals resistant to heat and that are abundant in rocky planets. 

(Witn inputs from PTI)