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Trajectory¤

Trajectory utilities for building source tracks in the center-of-mass frame, with optional annual parallax correction.

Classes¤

microlux.trajectory.TrajectoryParameters ¤

Bases: NamedTuple

A NamedTuple containing microlensing trajectory parameters.

Attributes:

Name Type Description
t0 ndarray

Time of closest approach.
u0 ndarray

Impact parameter at t0.
tE ndarray

Einstein timescale.
rho ndarray

Source radius in units of Einstein radius.
alpha_rad ndarray

Trajectory angle in radians.
s ndarray

Projected lens separation in Einstein-radius units.
q ndarray

Lens mass ratio.
pi_E_N ndarray

North component of microlensing parallax vector. Only used when annual parallax is enabled.
pi_E_E ndarray

East component of microlensing parallax vector. Only used when annual parallax is enabled.

microlux.trajectory.TrajectoryModel ¤

Bases: NamedTuple

A NamedTuple representing a trajectory model with optional annual parallax.

Attributes:

Name Type Description
times ndarray

Observation times in Julian Date.
delta_s ndarray | None

Annual parallax displacement projected on the sky plane in (North, East), shape (N, 2). If None, parallax correction is disabled.
photo_center bool

Whether to convert trajectory from center-of-mass coordinates to magnification-center coordinates for the s > 1 case.

calculate_trajectory(params: TrajectoryParameters | np.ndarray | jnp.ndarray) -> jnp.ndarray ¤

Calculate complex source trajectory at each epoch.

Parameters

  • params: One of:
  • TrajectoryParameters
  • Length-9 array: [t0, u0, tE, rho, alpha_rad, s, q, pi_E_N, pi_E_E]
  • Length-7 array: [t0, u0, tE, rho, alpha_rad, s, q] (parallax disabled)

Returns

  • trajectory: Complex trajectory array with shape (N,).

Functions¤

microlux.trajectory.get_trajectory_model(times: np.ndarray, coords: Coordinates, t0_par: float | None = None, photo_center: bool = False) -> TrajectoryModel ¤

Build a TrajectoryModel with optional annual parallax precomputation.

Parameters

  • times: Observation epochs in JD.
  • coords: Source sky coordinates used for annual parallax projection.
  • t0_par: Parallax reference epoch. If None, parallax is disabled.
  • photo_center: Whether to apply photocenter correction for s > 1.

Returns

  • trajectory_model: Trajectory model instance.

Notes

  • When t0_par is None, the model expects 7 trajectory parameters.
  • When t0_par is set, annual parallax is enabled and the model expects 9 trajectory parameters.