Exoplanet density and host star

Scientists found that the rocky exo-planet's density is affected by its host star Magnesium to iron content. Higher [Mg/Fe] content in the star → lower its planet density.

This holds when considering only F G K type (temperature near sun) stars.

They used high-resolution spectroscopy which measures how much light the star emits at specific wavelengths.

Elemental content (Fe, Mg, Si, Al, C, etc.) were obtained using spectral line fitting method. Each element absorbs light at specific wavelengths — the depth of these lines shows how much of that element is present.

They used a Bayesian regression method here.

To measure how strong the relation is between density and element ratio Pearson Correlation Coefficient was calculated.

Source: https://arxiv.org/html/2510.04981v1

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Tidal energy affects catastrophic threshold

 Catastrophic disruption threshold is a term used in planetary science and astrophysics to describe the minimum amount of energy required to completely break apart a celestial body (like an asteroid or satellite) so that it loses half or more of its total mass in a collision.

C constant depends on the effect of both tides and rotation.

δ measures orbital distance of the moon from the planet.

Qᴛᴅ (tidal-influenced catastrophic disruption threshold) decreases with the cube of distance  of moon from planet— the closer the moon, the easier to disrupt.

Source: https://iopscience.iop.org/article/10.3847/1538-4357/ae04e4

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