Astronomers from UCLA and the University of Warwick have discovered that stars entering the red giant phase can destroy giant planets orbiting too closely. The research results have been published in the journal Monthly Notices of the Royal Astronomical Society (MNRAS).
When a star runs out of hydrogen, it expands and cools, leaving behind the “main sequence.” Researchers have studied nearly half a million of these stars at the beginning of this phase. Scientists used data from the TESS satellite to identify 30 planets and planet candidates, including 33 previously unknown planets. The analysis shows that the more a star expands and cools, the less likely it is that large planets exist near it.
According to lead author Edward Bryant, as stars age, they cause nearby planets to spiral and die. The cause is tidal interaction: a gravitational “tug of war” between a star and a planet. Just as the Moon creates tides on Earth, the planet exerts pressure on the star, but as it expands, this pressure increases, causing the planet's orbit to slow until it “falls” into the star.
“In the distant future, a similar fate may await some planets in the solar system, when (in a few billion years) the Sun becomes a red giant. Earth will probably avoid being swallowed, but life on it at this time is unlikely to survive,” scientists predict.
