Astrometry

pyLIMA.astrometry.astrometric_positions.astrometric_positions_of_the_source(telescope, pyLIMA_parameters, time_ref=None)

The source astrometric positions without astrometric shifts

Parameters:

  • telescope (object, the telescope object containing astrometric data)

  • pyLIMA_parameters (dict, the dictionnary containing the model parameters)

  • time_ref (float, time of reference chosen, default is t0)

Returns:

  • position_ra (array, the astrometric position in North, degree or pixels)

  • position_dec (array, the astrometric position in East, degree or pixels)

pyLIMA.astrometry.astrometric_positions.lens_astrometric_positions(model, telescope, pyLIMA_parameters, time_ref=None)

The lens astrometric positions

Parameters:

  • model (object, the microlensing model object to compute the source trajectory) – relative to lens

  • telescope (object, the telescope object containing astrometric data)

  • pyLIMA_parameters (dict, the dictionnary containing the model parameters)

  • time_ref (float, time of reference chosen, default is t0)

Returns:

  • position_ra (array, the astrometric position in North, degree or pixels)

  • position_dec (array, the astrometric position in East, degree or pixels)

pyLIMA.astrometry.astrometric_positions.source_astrometric_positions(telescope, pyLIMA_parameters, shifts=None, time_ref=None)

The source astrometric positions with or without astrometric shifts

Parameters:

  • telescope (object, the telescope object containing astrometric data)

  • pyLIMA_parameters (dict, the dictionnary containing the model parameters)

  • shifts (array, North and East astrometric shifts in mas or pixel)

  • time_ref (float, time of reference chosen, default is t0)

Returns:

  • position_ra (array, the astrometric position in North, degree or pixels)

  • position_dec (array, the astrometric position in East, degree or pixels)

pyLIMA.astrometry.astrometric_positions.xy_shifts_to_NE_shifts(xy_shifts, piEN, piEE)

Transform the x,y positions into the North, East reference, i.e. rotate by phi = np.arctan2(piEE,piEN)

Parameters:

  • xy_shifts (array, the x and y positions)

  • piEN (float, the North component of the parallax vector)

  • piEE (float, a list of [string,float] indicating the xallarap model)

Returns:

  • Detlta_ra (array, the astrometric shift in North)

  • Detlta_dec (array, the astrometric shift in East)

pyLIMA.astrometry.astrometric_shifts.PSPL_shifts_no_blend(source_x, source_y, theta_E)

The PSPL astreomtric shifts without blend, see https: // arxiv.org / pdf / 1705.01767.pdf

Parameters:

  • source_x (array, the positions of the source in x)

  • source_y (array, the positions of the source in y)

  • theta_E (float, the angular Einsteing ring radius in mas)

Returns:

shifts

Return type:

array,the astrometric shifts, in x and y

pyLIMA.astrometry.astrometric_shifts.PSPL_shifts_with_blend(source_x, source_y, theta_E, g_blend)

The PSPL astreomtric shifts with blend, see https: // arxiv.org / pdf / 1705.01767.pdf

Parameters:

  • source_x (array, the positions of the source in x)

  • source_y (array, the positions of the source in y)

  • theta_E (float, the angular Einsteing ring radius in mas)

  • g_Blend (float, the blend_ratio, i.e. f_blend/f_source)

Returns:

shifts

Return type:

array,the astrometric shifts, in x and y