FaculaGenerator¶

class vspec_vsm.FaculaGenerator(dist_r_peak: ~astropy.units.quantity.Quantity, dist_r_logsigma: float, depth: ~astropy.units.quantity.Quantity, dist_life_peak: ~astropy.units.quantity.Quantity, dist_life_logsigma: float, floor_teff_slope: ~astropy.units.quantity.Quantity, floor_teff_min_rad: ~astropy.units.quantity.Quantity, floor_teff_base_dteff: ~astropy.units.quantity.Quantity, wall_teff_slope: ~astropy.units.quantity.Quantity, wall_teff_intercept: ~astropy.units.quantity.Quantity, coverage: float, dist: str = 'iso', grid_params: int | ~typing.Tuple[int, int] = (500, 1000), gridmaker: ~vspec_vsm.coordinate_grid.CoordinateGrid = None, rng: ~numpy.random._generator.Generator = Generator(PCG64) at 0x7F5F71E16DC0)¶

Bases: object

Facula Generator

Class controling the birth rates and properties of new faculae.

Parameters:

dist_r_peak (astropy.units.Quantity) – The peak of the radius distribution.
dist_r_logsigma (float) – The standard deviation of \(\log{r_0}\)
depth (astropy.units.Quantity) – The depth of the facula depression.
dist_life_peak (astropy.units.Quantity) – The peak of the lifetime distribution.
dist_life_logsigma (float) – The standard deviation of \(\log{\tau}\)
floor_teff_slope (astropy.units.Quantity) – The slope of the radius-Teff relationship
floor_teff_min_rad (astropy.units.Quantity) – The minimum radius at which the floor is visible. Otherwise the facula is a bright point – even near disk center.
floor_teff_base_dteff (astropy.units.Quantity) – The Teff of the floor at the minimum radius.
wall_teff_slope (astropy.units.Quantity) – The slope of the radius-Teff relationship
wall_teff_intercept (astropy.units.Quantity) – The Teff of the wall when \(R = 0\).
coverage (float) – The fraction of the surface covered by faculae in growth-deacay equilibrium.
dist (str) – Type of distribution. Currently only iso is supported.
nlat (int, default=VSPEC.config.nlat) – The number of latitude points on the stellar sufrace.
nlon (int, default=VSPEC.config.nlon) – The number of longitude points on the stellar surface.
gridmaker (CoordinateGrid, default=None) – A CoordinateGrid object to create the stellar sufrace grid.
rng (numpy.random.Generator, default=numpy.random.default_rng()) – The random number generator to use.

mean_area¶

dist_r_peak¶

The peak of the radius distribution.

Type:: astropy.units.Quantity

dist_r_logsigma¶

The standard deviation of \(\log{r_0}\)

Type:: float

depth¶

The depth of the facula depression.

Type:: astropy.units.Quantity

dist_life_peak¶

The peak of the lifetime distribution.

Type:: astropy.units.Quantity

dist_life_logsigma¶

The standard deviation of \(\log{\tau}\)

Type:: float

floor_teff_slope¶

The slope of the radius-Teff relationship

Type:: astropy.units.Quantity

floor_teff_min_rad¶

The minimum radius at which the floor is visible. Otherwise the facula is a bright point – even near disk center.

Type:: astropy.units.Quantity

floor_teff_base_dteff¶

The Teff of the floor at the minimum radius.

Type:: astropy.units.Quantity

wall_teff_slope¶

The slope of the radius-Teff relationship

Type:: astropy.units.Quantity

wall_teff_intercept¶

The Teff of the wall when \(R = 0\).

Type:: astropy.units.Quantity

coverage¶

The fraction of the surface covered by faculae in growth-deacay equilibrium.

Type:: float

dist¶

Type of distribution. Currently only iso is supported.

Type:: str

nlat¶

The number of latitude points on the stellar sufrace.

Type:: int

nlon¶

The number of longitude points on the stellar surface.

Type:: int

gridmaker¶

A CoordinateGrid object to create the stellar sufrace grid.

Type:: CoordinateGrid or None

rng¶

The random number generator to use.

Type:: numpy.random.Genrator

Attributes:

mean_area: The time-averaged area of a typical facula.

Methods

`birth_faculae`(time, rad_star)	Over a given time duration, compute the number of new faculae to create.
`generate_faculae`(n_to_generate)	Generate a given number of new Faculae
`get_coords`(n_to_generate)	Generate random coordinates for new Faculae to be centered at.
`get_n_faculae_expected`(time, rad_star)	Over a given time duration, compute the number of new faculae to create.
`off`([grid_params, gridmaker, rng])	An instance that does not generate any faculae.

Attributes Summary

mean_area

The time-averaged area of a typical facula.

Methods Summary

`birth_faculae`(time, rad_star)	Over a given time duration, compute the number of new faculae to create.
`generate_faculae`(n_to_generate)	Generate a given number of new Faculae
`get_coords`(n_to_generate)	Generate random coordinates for new Faculae to be centered at.
`get_n_faculae_expected`(time, rad_star)	Over a given time duration, compute the number of new faculae to create.
`off`([grid_params, gridmaker, rng])	An instance that does not generate any faculae.

Attributes Documentation

mean_area¶

The time-averaged area of a typical facula.

\[\bar{A} = \frac{ \pi r_0 ^2 (1-e^{-2}) }{2}\]

Type:: astropy.units.Quantity

Methods Documentation

birth_faculae(time: astropy.units.Quantity, rad_star: astropy.units.Quantity)¶

Over a given time duration, compute the number of new faculae to create. Create new faculae and assign them parameters.

Parameters:

time (astropy.units.Quantity) – Time over which to create faculae.
rad_star (astropy.units.Quantity) – Radius of the star.
Teff_star (astropy.units.Quantity) – Temperature of the star.

Returns:

Tuple of new faculae.

Return type:

tuple of Facula

generate_faculae(n_to_generate: int)¶

Generate a given number of new Faculae

Parameters:: n_to_generate (int) – The number of faculae to generate.
Returns:: Tuple of new faculae.
Return type:: tuple of Facula

get_coords(n_to_generate: int)¶

Generate random coordinates for new Faculae to be centered at.

Parameters:

n_to_generate (int) – The number of lat/lon pairs to create.

Returns:

lats (astropy.units.Quantity) – The latitude coordinates of the new faculae.
lons (astropy.units.Quantity) – The longitude coordinates of the new faculae.

Raises:

NotimplementedError – If dist is ‘solar’.
ValueError – If dist is not recognized.

get_n_faculae_expected(time: astropy.units.Quantity, rad_star: astropy.units.Quantity) → float¶

Over a given time duration, compute the number of new faculae to create.

Parameters:

time (astropy.units.Quantity) – Time over which to create faculae.
rad_star (astropy.units.Quantity) – Radius of the star.

Returns:

n_exp – The expected number of faculae to be birthed in the given time.

Return type:

float

Notes

\[N_{exp} = \frac{X 4 \pi R_* ^2 t}{2\tau \bar{A}}\]

For coverage fraction \(X\), stellar radius \(R_*\), time \(t\), lifetime \(\tau\), and time-averaged area \(\bar{A}\).

classmethod off(grid_params: int | ~typing.Tuple[int, int] = 1000, gridmaker: ~vspec_vsm.coordinate_grid.CoordinateGrid = None, rng: ~numpy.random._generator.Generator = Generator(PCG64) at 0x7F5F71E16EA0)¶

An instance that does not generate any faculae.

Parameters:

grid_params (int or tuple) – The number of latitude and longitude points on the stellar surface.
gridmaker (CoordinateGrid) – A CoordinateGrid object to create the stellar surface grid.
rng (numpy.random.generator) – The random number generator to use.