def get_bodies_in_orbit(m0, m_ffp, m_bp, a_bp, e_bp, phi_bp, lan_bp, b_ffp, r_inf):
#Bodies
bodies = Particles()
##Get BP in orbit
#Binary
star_planet = new_binary_from_orbital_elements(m0, m_bp, a_bp, e_bp, true_anomaly=phi_bp, inclination = 28, longitude_of_the_ascending_node = lan_bp)
#Planet attributes
star_planet.eccentricity = e_bp
star_planet.semimajoraxis = a_bp
#Center on the star
star_planet.position -= star_planet[0].position
star_planet.velocity -= star_planet[0].velocity
cm_p = star_planet.center_of_mass()
cm_v = star_planet.center_of_mass_velocity()
##Get FFP in orbit
#Particle set
m0_ffp = Particles(2)
#Zeros and parabolic velocity
zero_p = 0.0 | nbody_system.length
zero_v = 0.0 | nbody_system.speed
parabolic_velocity = get_parabolic_velocity(m0, m_ffp, b_ffp, r_inf, m_bp, a_bp, phi_bp)
#Central star
m0_ffp[0].mass = m0
m0_ffp[0].position = (zero_p,zero_p,zero_p)
m0_ffp[0].velocity = (zero_v,zero_v,zero_v)
#Free-floating planet
m0_ffp[1].mass = m_ffp
m0_ffp[1].position = (-r_inf-cm_p[0],-b_ffp-cm_p[1],zero_p)
m0_ffp[1].velocity = (parabolic_velocity,zero_v,zero_v)
#Orbital Elements
star_planet_as_one = Particles(1)
star_planet_as_one.mass = m0 + m_bp
star_planet_as_one.position = cm_p
star_planet_as_one.velocity = cm_v
binary = [star_planet_as_one[0], m0_ffp[1]]
m1, m2, sma, e = my_orbital_elements_from_binary(binary)
#For the star it sets the initial values of semimajoraxis and eccentricity of the ffp around star+bp
m0_ffp.eccentricity = e
m0_ffp.semimajoraxis = sma
#Order: star, ffp, bp
bodies.add_particle(m0_ffp[0])
bodies.add_particle(m0_ffp[1])
bodies.add_particle(star_planet[1])
return bodies
def get_ffp_in_orbit(m0, m_ffp, b, r_inf, parabolic_velocity):
m0_and_ffp_in_orbit = Particles(2)
zero_p = 0.0 | nbody_system.length
zero_v = 0.0 | nbody_system.speed
#Central star
m0_and_ffp_in_orbit[0].mass = m0
m0_and_ffp_in_orbit[0].position = (zero_p,zero_p,zero_p)
m0_and_ffp_in_orbit[0].velocity = (zero_v,zero_v,zero_v)
#Free-floating planet
m0_and_ffp_in_orbit[1].mass = m_ffp
m0_and_ffp_in_orbit[1].position = (-r_inf,-b,zero_p)
m0_and_ffp_in_orbit[1].velocity = (parabolic_velocity,zero_v,zero_v)
m1, m2, sma, e, ta, i, lan, ap = orbital_elements_from_binary(m0_and_ffp_in_orbit)
#For the star it sets the initial values of semimajoraxis and eccentricity of the ffp
m0_and_ffp_in_orbit.eccentricity = e
m0_and_ffp_in_orbit.semimajoraxis = sma
return m0_and_ffp_in_orbit
def get_bodies_in_orbit(m0, m_ffp, m_bp, a_bp, e_bp, phi_bp, inc_bp, lan_bp, b_ffp, r_inf):
#Bodies
bodies = Particles()
##Get BP in orbit
#Binary
star_planet = new_binary_from_orbital_elements(m0, m_bp, a_bp, e_bp, true_anomaly=phi_bp, inclination = inc_bp, longitude_of_the_ascending_node = lan_bp)
#Planet attributes
star_planet.eccentricity = e_bp
star_planet.semimajoraxis = a_bp
#Center on the star
star_planet.position -= star_planet[0].position
star_planet.velocity -= star_planet[0].velocity
cm_p = star_planet.center_of_mass()
cm_v = star_planet.center_of_mass_velocity()
##Get FFP in orbit
#Particle set
m0_ffp = Particles(2)
#Zeros and parabolic velocity
zero_p = 0.0 | nbody_system.length
zero_v = 0.0 | nbody_system.speed
parabolic_velocity = get_parabolic_velocity(m0, m_bp, b_ffp, r_inf)
#Central star
m0_ffp[0].mass = m0
m0_ffp[0].position = (zero_p,zero_p,zero_p)
m0_ffp[0].velocity = (zero_v,zero_v,zero_v)
#Free-floating planet
m0_ffp[1].mass = m_ffp
m0_ffp[1].position = (-r_inf+cm_p[0], b_ffp+cm_p[1], cm_p[2])
m0_ffp[1].velocity = (parabolic_velocity+cm_v[0], cm_v[1], cm_v[2])
#To find the orbital period of the BP
G = (1.0 | nbody_system.length**3 * nbody_system.time**-2 * nbody_system.mass**-1)
orbital_period_bp = 2*math.pi*((a_bp**3)/(G*m0)).sqrt()
#To find the distance and time to periastron
kep = Kepler()
kep.initialize_code()
star_planet_as_one = Particles(1)
star_planet_as_one.mass = m0 + m_bp
star_planet_as_one.position = cm_p
star_planet_as_one.velocity = cm_v
kepler_bodies = Particles()
kepler_bodies.add_particle(star_planet_as_one[0])
kepler_bodies.add_particle(m0_ffp[1])
kep.initialize_from_particles(kepler_bodies)
kep.advance_to_periastron()
time_pericenter = kep.get_time()
kep.stop()
binary = [star_planet_as_one[0], m0_ffp[1]]
sma, e, inclination, long_asc_node, arg_per = my_orbital_elements_from_binary(binary)
m0_ffp.eccentricity = e
m0_ffp.semimajoraxis = sma
#Adding bodies. Order: star, ffp, bp
bodies.add_particle(m0_ffp[0])
bodies.add_particle(m0_ffp[1])
bodies.add_particle(star_planet[1])
return bodies, time_pericenter, orbital_period_bp
