# Star¶

class mrspoc.Star(spots=None, u1=0.4987, u2=0.1772, r=1, radius_threshold=0.1, inclination=None)[source] [edit on github]

Bases: object

Object defining a star.

Parameters: u1 : float (optional) Quadratic limb-darkening parameter, linear term u2 : float (optional) Quadratic limb-darkening parameter, quadratic term r : float (optional) Stellar radius (default is unity) radius_threshold : float (optional) If all spots are smaller than this radius, use the analytic solution to compute the stellar centroid, otherwise use the numerical solution. spots : list (optional) List of spots on this star. inclination : Quantity Stellar inclination. Default is 90 deg.

Attributes Summary

 center_of_light Compute the center-of-light or centroid for this star, given its spots, and limb-darkening. inclination

Methods Summary

 derotate() limb_darkening(r) Compute the intensity at radius r for quadratic limb-darkening law with parameters Star.u1, Star.u2. limb_darkening_normed(r) Compute the normalized intensity at radius r for quadratic limb-darkening law with parameters Star.u1, Star.u2. plot([n, ax, col, col_exaggerate]) Plot a 2D projected schematic of the star and its spots. rotate(angle) Rotate the star, by moving the spots.

Attributes Documentation

center_of_light

Compute the center-of-light or centroid for this star, given its spots, and limb-darkening.

Returns: x_centroid : float Photocenter in the x dimension, in units of stellar radii y_centroid : float Photocenter in the y dimension, in units of stellar radii
inclination

Methods Documentation

derotate()[source] [edit on github]
limb_darkening(r)[source] [edit on github]

Compute the intensity at radius r for quadratic limb-darkening law with parameters Star.u1, Star.u2.

Parameters: r : float or ndarray Stellar surface position in radial coords on (0, 1) intensity : float Intensity in un-normalized units
limb_darkening_normed(r)[source] [edit on github]

Compute the normalized intensity at radius r for quadratic limb-darkening law with parameters Star.u1, Star.u2.

Parameters: r : float or ndarray Stellar surface position in radial coords on (0, 1) intensity : float Intensity relative to the intensity at the center of the disk.
plot(n=3000, ax=None, col=True, col_exaggerate=1)[source] [edit on github]

Plot a 2D projected schematic of the star and its spots.

Parameters: ax : Axes Axis object to draw the plot on col : bool (optional) Show the center of light with a red “x” if True col_exaggerate : float (optional) Exaggerate the center-of-light coordinate by this factor n : int Number of pixels per side in the image. ax : Axes Matplotlib axis object, with the new plot on it.
rotate(angle)[source] [edit on github]

Rotate the star, by moving the spots.

Parameters: angle : Quantity