Open science archive // Stellar spectroscopy // Exoplanetary chemistry
A systematic archive documenting the elemental chemistry of exoplanetary systems — measuring what stars are made of, and using that chemistry to understand what their planets are made of too.
Currently indexed: 12 systems · More added as analysis completes
The calibration anchor for all Codex measurements. Every [X/H] abundance is measured relative to the Sun. Solar EW results published. Abundance charts live.
A metal-rich K dwarf hosting five planets including Janssen — a lava super-Earth with a possible CO₂ atmosphere (JWST 2024). The C/O ratio of this star remains contested. We are measuring it.
Our nearest stellar neighbor. Candidate Saturn-mass planet detected by JWST MIRI; re-observation August 2026. Abundances in progress — HARPS 75 files complete, HST/MAST downloading.
HARPS spectra at R~115,000. Each absorption line in the stellar photosphere is a fingerprint of one element at one temperature and pressure.
Gaussian fitting to absorption lines yields equivalent widths — the area of each line — which map directly to elemental column densities.
ATLAS9/Castelli-Kurucz 1D LTE model atmospheres parameterized by Teff, log g, [Fe/H], and microturbulence. The same workhorse used since 1979.
Type A (random) and Type B (systematic) uncertainties documented for every measurement. Error bars are not optional — they are the science.
“This started as a senior astrophysics thesis in 2010 — three star systems, hand-fitted Gaussians, and a question: can you read the chemistry of a star and know what its planets are made of? I spent fifteen years building lasers and consulting on AI. The question never went away.”
We’re measuring 55 Cancri A now. Get notified when the first Codex entry publishes.