meepmeep.numba3d.sep

meepmeep.numba3d.sep(time: float | ndarray[tuple[Any, ...], dtype[_ScalarT]], tc: float, p: float, c: ndarray[tuple[Any, ...], dtype[_ScalarT]], te: float = 0.0) → float | ndarray[tuple[Any, ...], dtype[_ScalarT]]

Evaluate the sky-projected planet-star separation at an absolute time.

Folds the absolute observation time back to an expansion-point-centered offset and delegates to the centered kernel. This is the quantity most commonly used by transit light-curve models, where it represents the sky-projected separation between the centers of the star and planet in units of the stellar radius.

Accepts a scalar time or a 1-D array of times and dispatches to the appropriate kernel at compile time (inside @njit) or at call time (pure Python).

Parameters:

timefloat or NDArray

Absolute observation time(s).

tcfloat

Transit-centre time (time of inferior conjunction), on the same time axis as time.

pfloat

Orbital period.

cNDArray

A (3, 5) coefficient matrix produced by solve3d.

tefloat, optional

Expansion-point offset from the transit centre [days] - the same value that was passed to solve3d. Defaults to 0.0, the expansion point at the transit centre.

Returns:

dfloat or NDArray

Sky-projected planet-star separation in units of stellar radii. Always non-negative; the sign of the line-of-sight depth (transit vs. eclipse) is not encoded here. Use zpos or zpos_c if the transit/eclipse branch is needed.