Kepler#
This module contains a Kepler solver, Keplerian signal calculator, and various other helper functions.
- eurydice.kepler.calc_keplerian_signal(times, t_transit, period, ecc, omega, K)#
Compute the radial velocity signal of a transiting exoplanet
- Parameters:
times (np.array) – time measurements
t_transit (float) – time of transit
period (float) – period of orbit [days]
ecc (float) – eccentricity
omega (float) – longitude of periastron (radians)
K (float) – Keplarian semi-amplitude
- Returns:
array of radial velocity signals
- Return type:
(np.array)
- eurydice.kepler.calc_mean_anomaly(times, period, t_periastron)#
Compute the mean anomaly at given times during an orbit
- Parameters:
times (np.array) – times of measurement
period (float) – period of orbit [days]
t_periastron (float) – time of periastron passage
- Returns:
array of mean anomalies
- Return type:
(np.array)
- eurydice.kepler.calc_true_anomaly(E_anom, ecc)#
Compute the true anomaly at certain points during an orbit
- Parameters:
E_anom (np.array) – array of eccentric anomalies
ecc (float) – eccentricity
- Returns:
array of true anomalies
- Return type:
(np.array)
- eurydice.kepler.kepler_solver(M_anom, ecc, tolerance=1e-07)#
Solves Kepler’s equation using the Newton Raphson method
- Parameters:
M_anom (np.array) – array of mean anomalies
ecc (np.array) – array of eccentricities
tolerance (float, optional) – absolute tolerance of iterative computatiom (‘exit condition’). Defaults to 1e-7.
- Returns:
array of eccentric anomalies
- Return type:
(np.array)
- eurydice.kepler.transit_to_periastron(t_transit, period, ecc, omega)#
Convert Time of Transit to Time of Periastron Passage
- Parameters:
t_transit (float) – time of transit
period (float) – period of orbit [days]
ecc (float) – eccentricity
omega (float) – longitude of periastron (radians)
- Returns:
time of periastron passage
- Return type:
(float)