Khaberni - A new astronomical study published in "Monthly Notices of the Royal Astronomical Society" reveals that aging giant stars may turn into "planet killers," causing the swallowing or destruction of nearby planets as they naturally expand in their later stages.
Researchers have confirmed that planets orbiting their stars in 12 days or less are the most susceptible to this fate, with data showing a clear decline in the numbers of these planets around stars that have passed the main sequence stage.
The research team, which utilized data from the "TESS" satellite to explore exoplanets, noted that among more than 400,000 aging stars, 130 planets close to their stars were observed, including 33 new candidate planets.
The results indicated that the gas giants remaining near their stars at this stage constitute only 0.28 percent, compared to 0.35 percent in younger stars, with the percentage dropping to 0.11 percent in stars that have reached the red giant phase.
The lead author, Edward Brant from University College London and Warwick University, said: "These are strong indications that the evolution of stars quickly leads to planets rushing towards them and being destroyed. This subject has always been controversial, but now we clearly see it in extensive data."
He added: "We anticipated this, but were surprised by how efficiently these stars engulf their nearby planets."
The study suggests that planets closer to their stars face a greater risk, as tidal forces—similar to those between the Earth and the Moon—lead to the deterioration of their orbits until they meet their end. Gas giants may be crushed or torn apart before being swallowed by their stars.
Scientists expect the Sun to enter the post-main sequence phase in about 5 billion years. Although Earth might survive the red giant phase unlike Mercury and Venus, life on it would not be able to continue.
Co-researcher Vincent Van Eylen from University College London said: "Earth is in a better situation than the giant planets we studied, but it's not safe. We have only studied the early stage of star evolution, and the journey is long."
The team hopes to expand their understanding of this phenomenon using the upcoming PLATO space mission scheduled for launch in 2026, which is expected to provide a clearer view of older stars and the processes of planet swallowing.
