A tiny, regular dip in a distant star’s light first revealed the presence of a compact super‑Earth, its orbit traced by the transit method. Additional radial‑velocity measurements, tracking the star’s slight spectral shifts as it moved toward and away from observatories, pinned down the planet’s mass and orbital geometry with high precision.
With both radius and mass in hand, astronomers applied basic equations of bulk density and internal structure, finding a value too high for a water‑rich world but inconsistent with a purely silicate mantle like Earth’s. Spectroscopic data for the host star showed an elevated carbon‑to‑oxygen ratio, a chemical fingerprint that feeds directly into models of protoplanetary disk composition and phase diagrams for carbon under extreme pressure.
Those models, grounded in thermodynamics and mineral physics, indicate that in a carbon‑rich environment a massive rocky body can differentiate into layers where carbon crystallizes into diamond deep below the surface. The observed density, the stellar chemistry, and the constraints from orbital mechanics together do not prove the planet is a diamond sphere, but they make a diamond‑dominated interior a physically consistent solution to the data.
