Facula

class vspec_vsm.Facula(lat: astropy.units.Quantity, lon: astropy.units.Quantity, r_max: astropy.units.Quantity, r_init: astropy.units.Quantity, depth: astropy.units.Quantity, lifetime: astropy.units.Quantity, floor_teff_slope: astropy.units.Quantity, floor_teff_min_rad: astropy.units.Quantity, floor_teff_base_dteff: astropy.units.Quantity, wall_teff_slope: astropy.units.Quantity, wall_teff_intercept: astropy.units.Quantity, growing: bool = True, grid_params: int | Tuple[int, int] = (500, 1000), gridmaker: CoordinateGrid = None)

Bases: object

A small magnetic depression with a cool floor and hot walls.

Parameters:
_r
wall_dteff
floor_dteff
lat

Latitude of facula center.

Type:

astropy.units.Quantity

lon

Longitude of facula center.

Type:

astropy.units.Quantity

r_max

Maximum radius of facula.

Type:

astropy.units.Quantity

radius

Current radius of facula.

Type:

astropy.units.Quantity

depth

Depth of the depression.

Type:

astropy.units.Quantity

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

lifetime

Facula lifetime.

Type:

astropy.units.Quantity

is_growing

Whether or not the facula is still growing.

Type:

bool

gridmaker

A CoordinateGrid object to create the stellar sufrace grid.

Type:

CoordinateGrid object

Notes

The “Hot wall” model of solar facule describes them as a depression on the stellar surface with a hot wall and cool floor [Spruit, 1976]. Because if this, faculae appear bright when they are near the limb (hot wall is visible) and dark when near the disk center (cool floor is visible).

References

Attributes:
floor_dteff

The effective temperature difference between the photosphere and cool floor.

wall_dteff

The effective temperature difference between the photosphere and hot wall

Methods

age(time)

Progress the development of the facula by an amount of time.

angular_radius(star_rad)

Calculate the angular radius of the facula.

effective_area(angle)

Calculate the effective area of the floor and walls when projected on a disk.

fractional_effective_area(angle)

Calculate the fractional effective area as a fraction of the projected area of a region of quiet photosphere with the same radius and distance from limb.

map_pixels(star_rad)

Map pixels onto the surface of the facula.

set_gridmaker(gridmaker)

Attributes Summary

floor_dteff

The effective temperature difference between the photosphere and cool floor.

wall_dteff

The effective temperature difference between the photosphere and hot wall

Methods Summary

age(time)

Progress the development of the facula by an amount of time.

angular_radius(star_rad)

Calculate the angular radius of the facula.

effective_area(angle)

Calculate the effective area of the floor and walls when projected on a disk.

fractional_effective_area(angle)

Calculate the fractional effective area as a fraction of the projected area of a region of quiet photosphere with the same radius and distance from limb.

map_pixels(star_rad)

Map pixels onto the surface of the facula.

set_gridmaker(gridmaker)

Attributes Documentation

floor_dteff

The effective temperature difference between the photosphere and cool floor.

Type:

astropy.units.Quantity

wall_dteff

The effective temperature difference between the photosphere and hot wall

Type:

astropy.units.Quantity

Methods Documentation

age(time: astropy.units.Quantity)

Progress the development of the facula by an amount of time.

Parameters:

time (astropy.units.Quantity) – The amount of time to age facula.

Notes

This method calculates the new radius of the facula based on the amount of time elapsed since the last time it was updated. If the facula is still growing, it checks if it has reached the maximum radius and sets the is_growing attribute to False if so. If the facula is no longer growing, it shrinks over time.

angular_radius(star_rad: astropy.units.Quantity)

Calculate the angular radius of the facula.

Parameters:

star_rad (astropy.units.Quantity) – The radius of the star.

Returns:

The angular radius of the facula.

Return type:

astropy.units.Quantity

effective_area(angle)

Calculate the effective area of the floor and walls when projected on a disk.

Parameters:

angle (astropy.units.Quantity) – Angle from disk center.

Returns:

Effective area of the wall and floor. The keys are the Teff, the values are the area. Both are astropy.units.Quantity objects.

Return type:

dict

fractional_effective_area(angle: astropy.units.Quantity) → Dict[astropy.units.Quantity, astropy.units.Quantity]

Calculate the fractional effective area as a fraction of the projected area of a region of quiet photosphere with the same radius and distance from limb.

Parameters:

angle (astropy.units.Quantity) – Angle from disk center.

Returns:

Fractional effective area of the wall and floor. Keys are Teff.

Return type:

dictn_points=n_points

map_pixels(star_rad)

Map pixels onto the surface of the facula.

Parameters:

star_rad (astropy.units.Quantity) – The radius of the star.

Returns:

Boolean array indicating whether each pixel is within the facula radius.

Return type:

numpy.ndarray

set_gridmaker(gridmaker: CoordinateGrid)

Deprecated since version 0.1: Now that radius _r is a property is is not needed. The skeleton of this function is kept for compatibility.

Set the gridmaker attribute safely.

Parameters:

gridmaker (VSPEC.helpers.CoordinateGrid) – The CoordinateGrid object to set