A star’s internal chemistry can doom a planet’s life long before the star itself dies.
The search for potentially habitable planets involves discussion of what is sometimes referred to as the Goldilocks Zone – the relatively thin band in a solar system in which conditions on a planet can support life.
Astrobiologists and planetary scientists agree that a planet’s distance from its parent star is of paramount importance for creating those optimum conditions – like Goldilocks’ porridge, it has to be just right.
A new study by Arizona State University researchers suggests that the host star’s chemical makeup also can impact conditions of habitability of planets that orbit them. The team’s paper, published in the August issue of The Astrophysical Journal Letters, demonstrates that subtle differences in a star’s internal chemistry can have huge effects on a planet’s chances of long-term habitability.
“We have identified changes in the ratios of different elements as particularly important for a given solar system’s habitability,” says Patrick Young, an assistant professor in ASU’s School of Earth and Space Exploration and lead author on the paper. “The more abundant elements carbon, oxygen, silicon, magnesium and sodium are particularly important. The greater the abundances of these four elements in a star, the slower it, and the location of its Goldilocks Zone, will evolve.”
As a star evolves, it becomes brighter, causing the habitable zone to move outwards through its solar system. The team’s study indicates that a greater abundance of oxygen, carbon, sodium, magnesium and silicon should be a plus for an inner solar system’s long-term habitability because the abundance of these elements make the star cooler and cause it to evolve more slowly, thereby giving planets in its habitable zone more time to develop life as we know it. Via Stellar makeup impacts habitable zone evolution.