def update_orb_elem(host_star, planets, converter=None, kepler_worker=None):
if kepler_worker == None:
if converter == None:
tot_sys = Particles(particles=(host_star, planets))
converter = nbody_system.nbody_to_si(tot_sys.mass.sum(),
2 * host_star.radius)
kep_p = Kepler(unit_converter=converter, redirection='none')
kep_p.initialize_code()
else:
kep_p = kepler_worker
for planet in planets:
total_mass = host_star.mass + planet.mass
kep_pos = host_star.position - planet.position
kep_vel = host_star.velocity - planet.velocity
kep_p.initialize_from_dyn(total_mass, kep_pos[0], kep_pos[1],
kep_pos[2], kep_vel[0], kep_vel[1],
kep_vel[2])
planet.semimajor_axis, planet.eccentricity = kep_p.get_elements()
planet.period = kep_p.get_period()
planet.true_anomaly, planet.mean_anomaly = kep_p.get_angles()
if kepler_worker == None:
kep_p.stop()
def get_heirarchical_systems_from_set(bodies,
kepler_workers=None,
converter=None,
RelativePosition=False):
# Initialize Kepler
if kepler_workers == None:
if converter == None:
converter = nbody_system.nbody_to_si(
bodies.mass.sum(),
2 * np.max(bodies.radius.number) | bodies.radius.unit)
kep_p = Kepler(unit_converter=converter, redirection='none')
kep_p.initialize_code()
kep_s = Kepler(unit_converter=converter, redirection='none')
kep_s.initialize_code()
else:
kep_p = kepler_workers[0]
kep_s = kepler_workers[1]
# Seperate Out Planets and Stars from Bodies
stars, planets = util.get_stars(bodies), util.get_planets(bodies)
num_stars, num_planets = len(stars), len(planets)
# Initialize the Dictionary that Contains all Planetary Systems
systems = {}
# Initialize the List Used to Check Star IDs Against Already Classified Binaries
binary_ids = []
# Find Nearest Neighbors of the Set
closest_neighbours = stars.nearest_neighbour()
# Start Looping Through Stars to Find Bound Planets
for index, star in enumerate(stars):
# If the star is already in Binary_IDs, just go to the next star.
if star.id in binary_ids:
continue
# If not, Set the System ID and Set-up Data Structure.
system_id = star.id
current_system = systems.setdefault(system_id, Particles())
current_system.add_particle(star)
noStellarHierarchy = False
# If there is only one stars, there is obviously no stellar heirarchy in
# the encounter that is occuring.
if len(stars) == 1:
noStellarHierarchy = True
if not noStellarHierarchy:
# Check to see if the Nearest Neighbor is Mutual
star_neighbour_id = closest_neighbours[index].id
neighbour_neighbour_id = closest_neighbours[
stars.id == star_neighbour_id].id[0]
for other_star in (stars - star):
# Check to see if the two stars are bound.
kep_s.initialize_from_dyn(
star.mass + other_star.mass, star.x - other_star.x,
star.y - other_star.y, star.z - other_star.z,
star.vx - other_star.vx, star.vy - other_star.vy,
star.vz - other_star.vz)
a_s, e_s = kep_s.get_elements()
print(star.id, other_star.id, e_s)
# If they ARE NOT bound ...
if e_s >= 1.0:
noStellarHierarchy = True
# If they ARE bound ...
else:
# If the star is the star's neighbour's neighbour and visa-versa, then proceed.
print(star.id, other_star.id, star_neighbour_id,
neighbour_neighbour_id)
if star.id == neighbour_neighbour_id and other_star.id == star_neighbour_id:
noStellarHierarchy = False
print("Binary composed of Star", star.id, "and Star",
other_star.id, "has been detected!")
current_system.add_particle(other_star)
binary_ids.append(star.id)
binary_ids.append(other_star.id)
else:
print(
"!!! Alert: Bound Stars are not closest neighbours ..."
)
print("!!! Current Star:", star.id, "| Other Star:",
other_star.id)
print("!!! CS's Neighbour:", star_neighbour_id, \
"| CS's Neighbour's Neighbour:", neighbour_neighbour_id)
checked_planet_ids = []
for KeyID in systems.keys():
current_system = systems[KeyID]
sys_stars = util.get_stars(current_system)
noStellarHierarchy = False
# If there is only one stars, there is obviously no stellar heirarchy in
# the encounter that is occuring.
if len(sys_stars) == 1:
noStellarHierarchy = True
for planet in planets:
if planet.id in checked_planet_ids:
continue
star = sys_stars[sys_stars.id == KeyID][0]
total_mass = star.mass + planet.mass
kep_pos = star.position - planet.position
kep_vel = star.velocity - planet.velocity
kep_p.initialize_from_dyn(total_mass, kep_pos[0], kep_pos[1],
kep_pos[2], kep_vel[0], kep_vel[1],
kep_vel[2])
a_p, e_p = kep_p.get_elements()
P_p = kep_p.get_period()
Ta_p, Ma_p = kep_p.get_angles()
host_star_id = star.id
if e_p < 1.0:
# Check to See if The Planetary System is tied to a Stellar Binary
# Note: Things get complicated if it is ...
if noStellarHierarchy:
# Get Additional Information on Orbit
planet.semimajor_axis = a_p
planet.eccentricity = e_p
planet.period = P_p
planet.true_anomaly = Ta_p
planet.mean_anomaly = Ma_p
planet.host_star = star.id
# Add the Planet to the System Set
current_system.add_particle(planet)
else:
# Handling for Planetary Systems in Stellar Heirarchical Structures
# Note: We check to see which other star in the current systems
# have a better boundness with the planet and choose that
# as the new host star.
for other_star in sys_stars - star:
total_mass = other_star.mass + planet.mass
kep_pos = other_star.position - planet.position
kep_vel = other_star.velocity - planet.velocity
kep_p.initialize_from_dyn(total_mass, kep_pos[0],
kep_pos[1], kep_pos[2],
kep_vel[0], kep_vel[1],
kep_vel[2])
a_p2, e_p2 = kep_p.get_elements()
# Check to see if the planet is more bound to 'star' or
# 'other_star'. If its more bound to 'other_star',
# set the attributes to the more bound object. This will
# replace *_p with the better values with each loop.
if e_p2 < e_p:
a_p = a_p2
e_p = e_p2
P_p = kep_p.get_period()
Ta_p, Ma_p = kep_p.get_angles()
host_star_id = other_star.id
planet.semimajor_axis = a_p
planet.eccentricity = e_p
planet.period = P_p
planet.true_anomaly = Ta_p
planet.mean_anomaly = Ma_p
planet.host_star = host_star_id
# Add the Planet to the System Set
current_system.add_particle(planet)
checked_planet_ids.append(planet.id)
elif not noStellarHierarchy:
# Handling for Planetary Systems in Stellar Heirarchical Structures
# Note: We check to see which other star in the current systems
# have a better boundness with the planet and choose that
# as the new host star.
for other_star in sys_stars - star:
total_mass = other_star.mass + planet.mass
kep_pos = other_star.position - planet.position
kep_vel = other_star.velocity - planet.velocity
kep_p.initialize_from_dyn(total_mass, kep_pos[0],
kep_pos[1], kep_pos[2],
kep_vel[0], kep_vel[1],
kep_vel[2])
a_p2, e_p2 = kep_p.get_elements()
# Check to see if the planet is more bound to 'star' or
# 'other_star'. If its more bound to 'other_star',
# set the attributes to the more bound object. This will
# replace *_p with the better values with each loop.
if e_p2 < e_p:
a_p = a_p2
e_p = e_p2
P_p = kep_p.get_period()
Ta_p, Ma_p = kep_p.get_angles()
host_star_id = other_star.id
planet.semimajor_axis = a_p
planet.eccentricity = e_p
planet.period = P_p
planet.true_anomaly = Ta_p
planet.mean_anomaly = Ma_p
planet.host_star = host_star_id
# Add the Planet to the System Set
current_system.add_particle(planet)
else:
print(
"!!! Alert: Planet is not bound nor is it bound to any other star."
)
if kepler_workers == None:
kep_p.stop()
kep_s.stop()
return systems
def get_planetary_systems_from_set(bodies,
converter=None,
RelativePosition=False):
# Initialize Kepler
if converter == None:
converter = nbody_system.nbody_to_si(
bodies.mass.sum(),
2 * np.max(bodies.radius.number) | bodies.radius.unit)
kep_p = Kepler(unit_converter=converter, redirection='none')
kep_p.initialize_code()
kep_s = Kepler(unit_converter=converter, redirection='none')
kep_s.initialize_code()
# Seperate Out Planets and Stars from Bodies
stars, planets = util.get_stars(bodies), util.get_planets(bodies)
num_stars, num_planets = len(stars), len(planets)
# Initialize the Dictionary that Contains all Planetary Systems
systems = {}
# Start Looping Through Stars to Find Bound Planets
for star in stars:
system_id = star.id
#star.semimajor_axis, star.eccentricity, star.period, star.true_anomaly, star.mean_anomaly, star.kep_energy, star.angular_momentum = \
# None, None, None, None, None, None, None
current_system = systems.setdefault(system_id, Particles())
current_system.add_particle(star)
for planet in planets:
total_mass = star.mass + planet.mass
kep_pos = star.position - planet.position
kep_vel = star.velocity - planet.velocity
kep_p.initialize_from_dyn(total_mass, kep_pos[0], kep_pos[1],
kep_pos[2], kep_vel[0], kep_vel[1],
kep_vel[2])
a_p, e_p = kep_p.get_elements()
if e_p < 1.0:
# Check to See if The Stellar System is a Binary
# Note: Things get complicated if it is ...
noStellarHeirarchy = False
for other_star in (stars - star):
kep_s.initialize_from_dyn(
star.mass + other_star.mass, star.x - other_star.x,
star.y - other_star.y, star.z - other_star.z,
star.vx - other_star.vx, star.vy - other_star.vy,
star.vz - other_star.vz)
a_s, e_s = kep_s.get_elements()
r_apo = kep_s.get_apastron()
HillR = util.calc_HillRadius(a_s, e_s, other_star.mass,
star.mass)
if e_s >= 1.0 or HillR < r_apo:
noStellarHeirarchy = True
else:
noStellarHeirarchy = False
if noStellarHeirarchy:
# Get Additional Information on Orbit
planet.semimajor_axis = a_p
planet.eccentricity = e_p
planet.period = kep_p.get_period()
planet.true_anomaly, planet.mean_anomaly = kep_p.get_angles(
)
#planet.kep_energy, planet.angular_momentum = kep_p.get_integrals()
# Add the Planet to the System Set
current_system.add_particle(planet)
else:
# Handling for Planetary Systems in Stellar Heirarchical Structures
# Note: This is empty for now, maybe consider doing it by the heaviest bound stellar object as the primary.
pass
else:
continue
kep_p.stop()
kep_s.stop()
return systems
def get_orbit_ini(m0, m1, peri, ecc, incl, omega,
rel_force=0.01, r_disk=50|units.AU):
converter=nbody_system.nbody_to_si(1|units.MSun,1|units.AU)
# semi-major axis
if ecc!=1.0:
semi = peri/(1.0-ecc)
else:
semi = 1.0e10 | units.AU
# relative position and velocity vectors at the pericenter using kepler
kepler = Kepler_twobody(converter)
kepler.initialize_code()
kepler.initialize_from_elements(mass=(m0+m1), semi=semi, ecc=ecc, periastron=peri) # at pericenter
# moving particle backwards to radius r where: F_m1(r) = rel_force*F_m0(r_disk)
#r_disk = peri
r_ini = r_disk*(1.0 + numpy.sqrt(m1/m0)/rel_force)
kepler.return_to_radius(radius=r_ini)
rl = kepler.get_separation_vector()
r = [rl[0].value_in(units.AU), rl[1].value_in(units.AU), rl[2].value_in(units.AU)] | units.AU
vl = kepler.get_velocity_vector()
v = [vl[0].value_in(units.kms), vl[1].value_in(units.kms), vl[2].value_in(units.kms)] | units.kms
period_kepler = kepler.get_period()
time_peri = kepler.get_time()
kepler.stop()
# rotation of the orbital plane by inclination and argument of periapsis
a1 = ([1.0, 0.0, 0.0], [0.0, numpy.cos(incl), -numpy.sin(incl)], [0.0, numpy.sin(incl), numpy.cos(incl)])
a2 = ([numpy.cos(omega), -numpy.sin(omega), 0.0], [numpy.sin(omega), numpy.cos(omega), 0.0], [0.0, 0.0, 1.0])
rot = numpy.dot(a1,a2)
r_au = numpy.reshape(r.value_in(units.AU), 3, 1)
v_kms = numpy.reshape(v.value_in(units.kms), 3, 1)
r_rot = numpy.dot(rot, r_au) | units.AU
v_rot = numpy.dot(rot, v_kms) | units.kms
bodies = Particles(2)
bodies[0].mass = m0
bodies[0].radius = 1.0|units.RSun
bodies[0].position = (0,0,0) | units.AU
bodies[0].velocity = (0,0,0) | units.kms
bodies[1].mass = m1
bodies[1].radius = 1.0|units.RSun
bodies[1].x = r_rot[0]
bodies[1].y = r_rot[1]
bodies[1].z = r_rot[2]
bodies[1].vx = v_rot[0]
bodies[1].vy = v_rot[1]
bodies[1].vz = v_rot[2]
bodies.age = 0.0 | units.yr
bodies.move_to_center()
print "\t r_rel_ini = ", r_rot.in_(units.AU)
print "\t v_rel_ini = ", v_rot.in_(units.kms)
print "\t time since peri = ", time_peri.in_(units.yr)
a_orbit, e_orbit, p_orbit = orbital_parameters(r_rot, v_rot, (m0+m1))
print "\t a = ", a_orbit.in_(units.AU), "\t e = ", e_orbit, "\t period = ", p_orbit.in_(units.yr)
return bodies, time_peri
sun_and_stone = Particles(2)
sun_and_stone[0].position = [-5.40085336308e+13, -5.92288255636e+13, 0.
] | units.m
sun_and_stone[0].velocity = [-68.4281023588, -90.213640012, 0.
] | (units.m / units.s)
sun_and_stone[0].mass = 1.98892e+30 | units.kg
sun_and_stone[1].position = [2.31421952844e+17, 1.72742642121e+17, 0.
] | units.m
sun_and_stone[1].velocity = [500794.477878, 373808.365427, 0.
] | (units.m / units.s)
sun_and_stone[1].mass = 0. | units.kg
print " particles:"
print sun_and_stone
converter = nbody_system.nbody_to_si(1 | units.MSun, 1 | units.AU)
kepler = Kepler(converter)
kepler.initialize_code()
kepler.initialize_from_particles(sun_and_stone)
semi, ecc = kepler.get_elements()
apo = kepler.get_apastron()
per = kepler.get_periastron()
period = kepler.get_period()
kepler.stop()
print " semi-major axis ", semi.in_(units.AU)
print " eccentricity ", ecc
print " apocenter ", apo.in_(units.AU)
print " pericenter ", per.in_(units.AU)
print " period", period
def get_orbit_ini(m0,
m1,
peri,
ecc,
incl,
omega,
rel_force=0.01,
r_disk=50 | units.AU):
converter = nbody_system.nbody_to_si(1 | units.MSun, 1 | units.AU)
# semi-major axis
if ecc != 1.0:
semi = peri / (1.0 - ecc)
else:
semi = 1.0e10 | units.AU
# relative position and velocity vectors at the pericenter using kepler
kepler = Kepler_twobody(converter)
kepler.initialize_code()
kepler.initialize_from_elements(mass=(m0 + m1),
semi=semi,
ecc=ecc,
periastron=peri) # at pericenter
# moving particle backwards to radius r where: F_m1(r) = rel_force*F_m0(r_disk)
#r_disk = peri
r_ini = r_disk * (1.0 + numpy.sqrt(m1 / m0) / rel_force)
kepler.return_to_radius(radius=r_ini)
rl = kepler.get_separation_vector()
r = [
rl[0].value_in(units.AU), rl[1].value_in(units.AU), rl[2].value_in(
units.AU)
] | units.AU
vl = kepler.get_velocity_vector()
v = [
vl[0].value_in(units.kms), vl[1].value_in(units.kms), vl[2].value_in(
units.kms)
] | units.kms
period_kepler = kepler.get_period()
time_peri = kepler.get_time()
kepler.stop()
# rotation of the orbital plane by inclination and argument of periapsis
a1 = ([1.0, 0.0,
0.0], [0.0, numpy.cos(incl),
-numpy.sin(incl)], [0.0,
numpy.sin(incl),
numpy.cos(incl)])
a2 = ([numpy.cos(omega), -numpy.sin(omega),
0.0], [numpy.sin(omega), numpy.cos(omega), 0.0], [0.0, 0.0, 1.0])
rot = numpy.dot(a1, a2)
r_au = numpy.reshape(r.value_in(units.AU), 3, 1)
v_kms = numpy.reshape(v.value_in(units.kms), 3, 1)
r_rot = numpy.dot(rot, r_au) | units.AU
v_rot = numpy.dot(rot, v_kms) | units.kms
bodies = Particles(2)
bodies[0].mass = m0
bodies[0].radius = 1.0 | units.RSun
bodies[0].position = (0, 0, 0) | units.AU
bodies[0].velocity = (0, 0, 0) | units.kms
bodies[1].mass = m1
bodies[1].radius = 1.0 | units.RSun
bodies[1].x = r_rot[0]
bodies[1].y = r_rot[1]
bodies[1].z = r_rot[2]
bodies[1].vx = v_rot[0]
bodies[1].vy = v_rot[1]
bodies[1].vz = v_rot[2]
bodies.age = 0.0 | units.yr
bodies.move_to_center()
print "\t r_rel_ini = ", r_rot.in_(units.AU)
print "\t v_rel_ini = ", v_rot.in_(units.kms)
print "\t time since peri = ", time_peri.in_(units.yr)
a_orbit, e_orbit, p_orbit = orbital_parameters(r_rot, v_rot, (m0 + m1))
print "\t a = ", a_orbit.in_(
units.AU), "\t e = ", e_orbit, "\t period = ", p_orbit.in_(units.yr)
return bodies, time_peri
