SpotParameters#

class VSPEC.params.stellar.SpotParameters(distribution: str, initial_coverage: float, area_mean: astropy.units.Quantity, area_logsigma: float, teff_umbra: astropy.units.Quantity, teff_penumbra: astropy.units.Quantity, equillibrium_coverage: float, burn_in: astropy.units.Quantity, growth_rate: astropy.units.Quantity, decay_rate: astropy.units.Quantity, initial_area: astropy.units.Quantity)#

Bases: BaseParameters

Parameters controling variability from star spots.

Parameters:

distribution (str) – The distribution function to be used for the spot positions. Either iso for an isotropic distribution or solar for two bands at \(\pm 15^\circ\) latitude.
initial_coverage (float) – The spot coverage created initially by generating spots at random stages of life.
area_mean (astropy.units.Quantity) – The mean area of a spot on the star’s surface is MSH.
area_logsigma (float) – The standard deviation of the spot areas. This is a lognormal distribution, so the units of this value are dex.
teff_umbra (astropy.units.Quantity) – The effective temperature of the spot umbrae.
teff_penumbra (astropy.units.Quantity) – The effective temperature of the spot penumbrae.
equillibrium_coverage (float) – The fractional coverage of the star’s surface by spots. This is the value at growth-decay equillibrium.
burn_in (astropy.units.Quantity) – The duration of the burn-in period, during which the spot coverage approaches equillibrium.
growth_rate (astropy.units.Quantity) – The rate at which new spots grow.
decay_rate (astropy.units.Quantity) – The rate at which existing spots decay.
initial_area (astropy.units.Quantity) – The initial area of newly created spots.

distribution#

The distribution function to be used for the spot positions. ‘iso’ or ‘solar’.

Type:: str

initial_coverage#

The coverage for a ‘hot start’.

Type:: float

area_logmean#

The mean area of a spot on the star’s surface is MSH.

Type:: float

area_logsigma#

The standard deviation of the spot areas. This is a lognormal distribution, so the units of this value are dex.

Type:: float

teff_umbra#

The effective temperature of the spot umbrae.

Type:: astropy.units.Quantity

teff_penumbra#

The effective temperature of the spot penumbrae.

Type:: astropy.units.Quantity

equillibrium_coverage#

The fractional coverage of the star’s surface by spots. This is the value at growth-decay equillibrium, and different from the ‘hot start’ value given by initial_coverage.

Type:: float

burn_in#

The duration of the burn-in period, during which the spot coverage approaches equillibrium.

Type:: astropy.units.Quantity

growth_rate#

The rate at which new spots grow.

Type:: astropy.units.Quantity

decay_rate#

The rate at which existing spots decay.

Type:: astropy.units.Quantity

initial_area#

The initial area of newly created spots.

Type:: astropy.units.Quantity

classmethod from_preset(name)#

Load a SpotParameters instance from a preset file.

Parameters:: name (str) – The name of the preset to load.
Returns:: The class instance loaded from a preset.
Return type:: SpotParameters

classmethod mdwarf()#: Static Spots

classmethod none()#: No spots

classmethod solar()#: Solar-style spots

to_generator(grid_params: int | ~typing.Tuple[int, int] = (500, 1000), gridmaker: ~vspec_vsm.coordinate_grid.CoordinateGrid = None, rng: ~numpy.random._generator.Generator = Generator(PCG64) at 0x7F7337AFDB60) → SpotGenerator#

Create a vspec_vsm.SpotGenerator instance from the class instance.

Parameters:

grid_params (Union[int, Tuple[int, int]], optional) – If tuple, the number of grid points in the latitude and longitude directions. If int, the number of total grid points for a sprial grid. Defaults to (vsm_config.NLAT, vsm_config.NLON).
gridmaker (CoordinateGrid, optional) – An instance of vspec_vsm.CoordinateGrid to use for the grid. Defaults to None.
rng (np.random.Generator, optional) – The random number generator to use. Defaults to np.random.default_rng().

Returns:

The vspec_vsm.SpotGenerator instance.

Return type:

vspec_vsm.SpotGenerator