# Star¶

Instances of Star are objects representing a model star. A model star is constituted by:

• an ambient Schwarzschild spacetime solution;
• a discrete representation (on leaves of a spacetime foliation) of an embedded stellar 2-surface exterior to which the ambient spacetime solution is assumed valid;
• a discrete representation of the local comoving source radiation field in time and photon phase-space over the stellar 2-surface;
• a discrete representation of the time-invariant null mapping from the stellar 2-surface to effective infinity;
• and low-level integrators of the radiation field incident in the neighbourhood of a point at effective infinity to obtain pulses.
class xpsi.Star.Star(spacetime, photospheres)[source]

Instances of Star represent model stars.

Each model star is abstractly constructed from an ambient spacetime, Spacetime, and a collection of photosphere objects which are each embedded in that ambient spacetime for disjoint intervals of coordinate time.

Parameters: spacetime (obj) – An instance of Spacetime. photospheres (list) – Each element must be an instance of Photosphere.
photospheres

Get the list of photosphere objects.

update(fast_counts=None, threads=1)[source]

Update the star.

Parameters: fast_counts (tuple) – Total count numbers from two or more temperature components of a hot region. Each tuple element is itself a tuple over hot regions, and if a hot region has two temperature components that were integrated over during the fast mode, the total counts per component are elements of another tuple. This nested containerisation is handled automatically. threads (int) – Number of OpenMP threads to spawn for embedding photosphere objects in the ambient spacetime.