Keplerian Orbits

radvel.kepler.kepler(Marr, eccarr)

Solve Kepler’s Equation :param Marr: input Mean anomaly :type Marr: array :param eccarr: eccentricity :type eccarr: array

Returns:eccentric anomaly Return type:array

radvel.kepler.rv_drive(t, orbel, use_c_kepler_solver=True)

RV Drive :param t: times of observations :type t: array of floats :param orbel: [per, tp, e, om, K]. Omega is expected to be in radians :type orbel: array of floats :param use_c_kepler_solver: (default: True) If True use the Kepler solver written in C, else use the Python/NumPy version. :type use_c_kepler_solver: bool

Returns:(array of floats): radial velocity model Return type:rv

radvel.orbit.timeperi_to_timetrans(tp, per, ecc, omega, secondary=False)

Convert Time of Periastron to Time of Transit

Parameters:

• tp (float) – time of periastron
• per (float) – period [days]
• ecc (float) – eccentricity
• omega (float) – argument of peri (radians)
• secondary (bool) – calculate time of secondary eclipse instead

Returns:

time of inferior conjunction (time of transit if system is transiting)

Return type:

float

radvel.orbit.timetrans_to_timeperi(tc, per, ecc, omega)

Convert Time of Transit to Time of Periastron Passage

Parameters:

• tc (float) – time of transit
• per (float) – period [days]
• ecc (float) – eccentricity
• omega (float) – longitude of periastron (radians)

Returns:

time of periastron passage

Return type:

float

radvel.orbit.true_anomaly(t, tp, per, e)

Calculate the true anomaly for a given time, period, eccentricity.

Parameters:

• t (array) – array of times in JD
• tp (float) – time of periastron, same units as t
• per (float) – orbital period in days
• e (float) – eccentricity

Returns:

true anomoly at each time

Return type:

array