Star and orbit
The [star] section configures the host star model and spectral properties.
The [orbit] section configures the planetary orbit, tidal evolution, and
any satellite.
Submodule documentation: MORS | Obliqua. See also Model description.
Stellar model [star]
| Parameter | Type | Default | Description |
|---|---|---|---|
module |
str | "mors" |
Stellar evolution module: mors (age-dependent tracks) or dummy (fixed properties) |
mass |
float | 1.0 |
Stellar mass [M\(_\odot\)] |
age_ini |
float | 0.1 |
Model start age [Gyr] |
bol_scale |
float | 1.0 |
Bolometric luminosity scaling factor |
MORS stellar tracks [star.mors]
The MORS module interpolates stellar radius, effective temperature, luminosity, and XUV flux from pre-computed evolutionary tracks as a function of stellar age. Two track families are available: Spada1 (solar-type) and Baraffe2 (low-mass M-dwarfs).
| Parameter | Type | Default | Description |
|---|---|---|---|
tracks |
str | "spada" |
Evolution track family: spada or baraffe |
age_now |
float | 4.567 |
Observed or estimated stellar age [Gyr] |
rot_pcntle |
float or none | 50.0 |
Rotation percentile of stellar population [0, 100] |
rot_period |
float or none | none |
Rotation period [days]; overrides rot_pcntle if set |
spectrum_source |
str | "phoenix" |
Spectral library: solar, muscles, phoenix |
star_name |
str or none | none |
Named star for solar/muscles lookup (e.g. "sun", "trappist-1") |
star_path |
str or none | none |
Path to custom spectrum file; overrides spectrum_source |
PHOENIX synthetic spectra
These parameters are used when spectrum_source = "phoenix". PHOENIX provides
synthetic spectra on a grid of metallicity, alpha enhancement, and (optionally)
effective temperature.
| Parameter | Type | Default | Description |
|---|---|---|---|
phoenix_FeH |
float | 0.0 |
Metallicity [Fe/H]; 0.0 = solar |
phoenix_alpha |
float | 0.0 |
Alpha enhancement [\(\alpha\)/Fe]; 0.0 = solar |
phoenix_radius |
float or none | none |
Stellar radius [R\(_\odot\)]; none = from MORS tracks |
phoenix_log_g |
float or none | none |
Surface gravity [log\(_{10}\) cgs]; none = from MORS tracks |
phoenix_Teff |
float or none | none |
Effective temperature [K]; none = from MORS tracks |
Dummy star [star.dummy]
A fixed-luminosity star with no temporal evolution. Useful for testing and parameter studies where stellar evolution is not relevant.
| Parameter | Type | Default | Description |
|---|---|---|---|
Teff |
float | 5772.0 |
Effective temperature [K] |
radius |
float or none | none |
Stellar radius [R\(_\odot\)]; if none, derived from Teff and mass when calculate_radius = true |
calculate_radius |
bool | false |
Derive radius from mass-luminosity and mass-radius relations |
Orbital configuration [orbit]
| Parameter | Type | Default | Description |
|---|---|---|---|
module |
str or none | none |
Tidal heating module: none (no tides), dummy (fixed heating), lovepy (self-consistent Love numbers) |
semimajoraxis |
float | 1.0 |
Orbital semi-major axis [AU] |
eccentricity |
float | 0.0 |
Orbital eccentricity |
instellation_method |
str | "distance" |
How to define the orbit: distance (use semi-major axis) or inst (use instellation flux) |
instellationflux |
float | 1.0 |
Instellation flux [S\(_\oplus\)] (only used when method = "inst") |
zenith_angle |
float | 48.19 |
Characteristic zenith angle [degrees] |
s0_factor |
float | 0.375 |
Instellation geometric scale factor (accounts for rotation and day-night redistribution) |
evolve |
bool | false |
Evolve semi-major axis and eccentricity via tidal dissipation |
axial_period |
float or none | none |
Planetary rotation period [hours]; none = tidally locked (1:1 spin-orbit resonance) |
Satellite
| Parameter | Type | Default | Description |
|---|---|---|---|
satellite |
bool | false |
Include a satellite (moon) |
mass_sat |
float | 7.347e22 |
Satellite mass [kg] (default: lunar mass) |
semimajoraxis_sat |
float | 3e8 |
Satellite orbital semi-major axis [m] |
Dummy tides [orbit.dummy]
Fixed tidal heating rates, useful for parameter studies.
| Parameter | Type | Default | Description |
|---|---|---|---|
H_tide |
float | 0.0 |
Fixed tidal power density [W kg\(^{-1}\)] |
Phi_tide |
str | "<0.3" |
Inequality defining where tidal heating is applied (melt fraction condition, e.g. "<0.3") |
Imk2 |
float | 0.0 |
Fixed Im(\(k_2\)) Love number (must be \(\leq 0\)) |
LovePy tides [orbit.lovepy]
Self-consistent tidal heating using viscoelastic Love numbers computed from the interior rheological profile.
| Parameter | Type | Default | Description |
|---|---|---|---|
visc_thresh |
float | 1e9 |
Minimum viscosity for tidal heating calculation [Pa s] |
ncalc |
int | 1000 |
Number of interior grid points for tidal calculation |
See also: Stellar module | Orbit module
-
Spada, F., Demarque, P., Kim, Y.C. & Sills, A., The radius discrepancy in low-mass stars: single versus binaries, The Astrophysical Journal, 776, 87, 2013. SciX. ↩
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Baraffe, I., Homeier, D., Allard, F. & Chabrier, G., New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit, Astronomy & Astrophysics, 577, A42, 2015. SciX. ↩