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Reference data

This page documents the reference datasets that PROTEUS uses at runtime: where they come from, what they contain, and how they are identified in config files. For instructions on switching between spectrum sources, see Switch and choose a stellar spectrum.

Automatic data download

PROTEUS downloads reference data from Zenodo on first run. If Zenodo is unavailable, each dataset falls back automatically to its corresponding project on the Open Science Framework (OSF). A Zenodo API token is optional; without one, public access is used with lower rate limits.

Dataset Downloaded by
Stellar spectra (solar, MUSCLES) proteus get solar, proteus get muscles
PHOENIX synthetic spectra proteus get phoenix
Stellar evolution tracks proteus get stellar
Spectral k-tables proteus get spectral
Surface albedos proteus get surfaces
Scattering properties proteus get scattering
Exoplanet populations, mass-radius curves proteus get reference
Interior EOS tables, melting curves proteus get interiordata

To configure a Zenodo API token, see the Troubleshooting guide.

Stellar spectra

The spectrum source is set via star.mors.spectrum_source and star.mors.star_name (or star.mors.star_path for a custom file). See Switch and choose a stellar spectrum for full usage instructions.

Solar spectra

Observed solar spectra are stored under $FWL_DATA/stellar_spectra/solar/. The modern spectrum is from Gueymard (2003) via NREL. Historical and future spectra are from Claire et al. (2012).

star_name Description Age of Sun
sun Modern NREL spectrum 4.6 Gyr
SunModern Alternative modern solar spectrum 4.6 Gyr
Sun0.6Ga 0.6 Gyr ago ~4.0 Gyr
Sun1.8Ga 1.8 Gyr ago ~2.8 Gyr
Sun2.4Ga 2.4 Gyr ago ~2.2 Gyr
Sun2.7Ga 2.7 Gyr ago ~1.9 Gyr
Sun3.8Ga 3.8 Gyr ago ~800 Myr
Sun4.4Ga 4.4 Gyr ago ~200 Myr
Sun5.6Gyr Future Sun 5.6 Gyr

star_name matching is case-insensitive.

MUSCLES / Mega-MUSCLES spectra

Observed UV–optical–IR spectra from the MUSCLES and Mega-MUSCLES surveys, stored under $FWL_DATA/stellar_spectra/MUSCLES/ as <star_name>.txt. star_name matching is case-insensitive.

Full star catalog
Star star_name Type Teff (K) Age L (L☉) M (M☉) R (R☉) Survey
Epsilon Eridani v-eps-eri K2V 5020 400–800 Myr 0.32 0.82 0.759 MUSCLES
GJ 1132 gj1132 M4.5V 3229 — 0.005 0.195 0.221 Mega-MUSCLES
GJ 1214 gj1214 M4V 3100 5–10 Gyr 0.00351 0.182 0.216 MUSCLES
GJ 15 A gj15a M1–M2V ~3700 — ~0.021 ~0.40 ~0.38 Mega-MUSCLES
GJ 163 gj163 M3.5V ~3300–3500 ~2–10 Gyr ~0.02 ~0.40 ~0.41 Mega-MUSCLES
GJ 176 gj176 M2.5V ~3700 ~4 Gyr 0.034 0.51 0.48 MUSCLES
GJ 436 gj436 M2.5–M3V ~3600 ~6–15 Gyr 0.023 0.44 0.42 MUSCLES
GJ 551 (Proxima Cen) gj551 M5.5Ve ~2900–3000 ~4.8 Gyr 0.0015 0.12 0.14 MUSCLES
GJ 581 gj581 M3V ~3500 ~4 Gyr ~0.012 ~0.30 ~0.30 MUSCLES
GJ 649 gj649 M1–M2V ~3700 — ~0.044 0.51 0.50 Mega-MUSCLES
GJ 667 C gj667c M1.5V ~3700 >2 Gyr ~0.014 ~0.33 ~0.32–0.42 MUSCLES
GJ 674 gj674 M2.5V ~3400–3600 ~0.5–3 Gyr 0.017 0.35 0.36 Mega-MUSCLES
GJ 676 A gj676a M0V ~3800–4000 — 0.083 0.63 0.65 Mega-MUSCLES
GJ 699 (Barnard's Star) gj699 M3.5–4V ~3200–3300 ~10 Gyr 0.0035 ~0.16 ~0.19 Mega-MUSCLES
GJ 729 (Ross 154) gj729 M3.5V ~3200–3300 <1–2 Gyr ~0.004–0.005 ~0.18 ~0.20 Mega-MUSCLES
GJ 832 gj832 M1–M3V ~3500 ~4–12 Gyr ~0.03 0.45 0.45 MUSCLES
GJ 832 (synthetic) gj832_synth M1–M3V ~3500 ~4–12 Gyr ~0.03 0.45 0.45 MUSCLES
GJ 849 gj849 M3.5V 3467 >3 Gyr 0.02887 0.45 0.45 Mega-MUSCLES
GJ 876 gj876 M2–4V ~3200–3300 ~2–15 Gyr ~0.013 ~0.37 ~0.37 MUSCLES
HAT-P-12 hat-p-12 K4V 4500–4800 2–14 Gyr ~0.20 0.74 0.70 MUSCLES ext.
HAT-P-26 hat-p-26 K1V ~5050 4–12 Gyr ~0.44 0.85 0.86 MUSCLES ext.
HD 40307 hd40307 K2.5V ~4800–5000 ~2–5 Gyr ~0.22 ~0.79 ~0.71 MUSCLES
HD 85512 hd85512 M0V ~4400 ~6 Gyr 0.17 0.69 0.69 MUSCLES
HD 97658 hd97658 K1V 5212 3.9 Gyr 0.351 0.773 0.728 MUSCLES
HD 149026 hd-149026 G0V ~6100–6200 ~2–3 Gyr ~2.6 ~1.14 ~1.46 MUSCLES ext.
L 98-59 l-98-59 M3V 3415 ~5 Gyr 0.012 0.292 0.316 Mega-MUSCLES
L 678-39 (GJ 357) l-678-39 M2.5V ~3500 — 0.0017 ~0.34 ~0.34 MUSCLES ext.
L 980-5 l-980-5 M4V — — — — — Mega-MUSCLES
LHS 2686 lhs-2686 M5V — — — — — Mega-MUSCLES
LP 791-18 lp-791-18 M6V ~2960 >0.5 Gyr ~0.002 0.139 0.182 MUSCLES ext.
TOI-193 (LTT 9779) toi-193 G7V ~5400–5500 ~2 Gyr ~0.7 ~1.0 ~0.95 MUSCLES ext.
TRAPPIST-1 trappist-1 M8V 2566 ~8 Gyr 0.000553 0.0898 0.1192 Mega-MUSCLES
WASP-17 wasp-17 F4–F6V ~6550 ~3 Gyr ~4 1.35 1.57 MUSCLES ext.
WASP-43 wasp-43 K7V ~4100 ~7 Gyr ~0.15 ~0.65 ~0.76 MUSCLES ext.
WASP-77 A wasp-77a G8V ~5600 ~6 Gyr ~0.74 ~0.90 ~0.91 MUSCLES ext.
WASP-127 wasp-127 G5 ~5600–5800 ~10–12 Gyr ~1.8 ~0.95–1.10 ~1.3 MUSCLES ext.

PHOENIX synthetic spectra

Med-resolution synthetic spectra from the PHOENIX library, stored under $FWL_DATA/stellar_spectra/PHOENIX/<FeH>_<alpha>/. Each subdirectory corresponds to one metallicity–alpha combination (e.g. FeH-0.5_alpha+0.0/).

Parameters defining the PHOENIX grid:

Parameter Config key Unit Default
Effective temperature phoenix_Teff K Derived from MORS tracks
Surface gravity phoenix_log_g log\(_{10}\) (cgs) Derived from MORS tracks
Stellar radius phoenix_radius R\(_\odot\) Derived from MORS tracks
Metallicity phoenix_FeH [Fe/H] dex 0.0 (solar)
Alpha enhancement phoenix_alpha [α/Fe] dex 0.0 (solar)

Any parameter set to "none" in the config is derived from the MORS stellar evolution tracks using star.mass. Grid inputs are automatically rounded to the nearest available grid point.

Custom stellar spectrum

A user-supplied spectrum is loaded when star.mors.star_path is set. It overrides spectrum_source, star_name, and all phoenix_* parameters. Environment variables (e.g. $FWL_DATA, $HOME) in the path are expanded at load time.

Required file format:

Column Quantity Unit
1 Wavelength nm
2 Flux erg s\(^{-1}\) cm\(^{-2}\) nm\(^{-1}\)

The spectrum must be scaled to a distance of 1 AU. Comment lines begin with #.

Spectral files

Correlated-k opacity tables used by the atmosphere climate modules (AGNI, JANUS). Selected via atmos_clim.spectral_group and atmos_clim.spectral_bands in the config. Stored under $FWL_DATA/spectral_files/<group>/<bands>/. For a full description of each group's spectral coverage and gas species, see docs/assets/spectral_files.pdf in the PROTEUS repository.

Group Available band counts Notes
Honeyside 16, 48, 256, 4096 Default; broad gas coverage
Dayspring 16, 48, 256, 4096
Frostflow 16, 48, 256, 4096
Oak 318

The default configuration uses Honeyside / 48. Higher band counts increase spectral resolution and runtime cost.

Surfaces

Single-scattering albedo data from Hammond et al. (2024): Zenodo record 13691960.

Available surface types can be listed with:

ls $FWL_DATA/surface_albedos/Hammond24

Exoplanet population data

Obtained from the DACE PlanetS database (Parc et al., 2024).

Mass-radius relations

Obtained from Zeng et al. (2016).

Equations of state

The interior structure solver of PROTEUS, Zalmoxis, uses equation-of-state tables by Seager et al. (2007), and from PALEOS by Attia et al. (2026). An overview of equation of state tables can be found here.