def main(args):
if len(args) == 1:
time = Time.Now()
elif len(args) == 2:
time = Time.Parse(args[1])
else:
print('USAGE: {} [yyyy-mm-ddThh:mm:ssZ]'.format(args[0]))
return 1
# Get the Moon phase at the starting time, so we know what
# multiple of 12 degrees to search for next.
phase = MoonPhase(time)
print("{} : Moon's phase angle = {:0.6f} degrees.".format(time, phase))
print()
print('The next 30 lunar days are:')
target = 12.0 * math.ceil(phase / 12.0)
for _ in range(30):
time = SearchMoonPhase(target, time, 2.0)
if time is None:
print('SEARCH FAILURE.')
return 0
d = 1 + int(target / 12)
print('{} : Lunar Day {}'.format(time, d))
target = math.fmod(target + 12.0, 360.0)
return 0
def main(args):
if len(args) == 1:
time = Time.Now()
elif len(args) == 2:
time = Time.Parse(args[1])
else:
print('USAGE: {} [yyyy-mm-ddThh:mm:ssZ]'.format(args[0]))
return 1
count = 0
e = SearchLunarEclipse(time)
while count < 10:
if e.kind != EclipseKind.Penumbral:
count += 1
PrintEclipse(e)
e = NextLunarEclipse(e.peak)
def GraphPairLongitude(body1, body2, t1, t2, npoints):
xlist = []
ylist = []
for i in range(npoints + 1):
ut = t1.ut + ((i / npoints) * (t2.ut - t1.ut))
time = Time(ut)
lon = PairLongitude(body1, body2, time)
xlist.append(ut)
ylist.append(lon)
plt.plot(xlist, ylist, 'b.')
plt.show()
plt.close('all')
tx, cx = FindConstellationChange(body, c1, t1, t2)
print('{} : {} leaves {} and enters {}.'.format(
tx, body.name, c1.name, cx.name))
c1 = cx
t1 = tx
else:
# No constellation change in this time step. Try again on the next time step.
c1 = c2
t1 = t2
#------------------------------------------------------------------------------
if __name__ == '__main__':
if len(sys.argv) == 1:
startTime = Time.Now()
elif len(sys.argv) == 2:
startTime = Time.Parse(sys.argv[1])
else:
print('USAGE: {} [yyyy-mm-ddThh:mm:ssZ]'.format(sys.argv[0]))
sys.exit(1)
stopTime = startTime.AddDays(30.0)
# There are 12 zodiac constellations, and the moon takes
# about 27.3 days in its sidereal period. Therefore, there
# are roughly 2.2 days per constellation. We will sample
# the Moon's constellation once every 0.1 days to reduce
# the chance of missing a brief transition through a small
# part of a constellation.
dayIncrement = 0.1
rc = FindConstellationChanges(Body.Moon, startTime, stopTime, dayIncrement)
sys.exit(rc)
def GraphPairLongitude(body1, body2, t1, t2, npoints):
xlist = []
ylist = []
for i in range(npoints + 1):
ut = t1.ut + ((i / npoints) * (t2.ut - t1.ut))
time = Time(ut)
lon = PairLongitude(body1, body2, time)
xlist.append(ut)
ylist.append(lon)
plt.plot(xlist, ylist, 'b.')
plt.show()
plt.close('all')
if __name__ == '__main__':
if not (5 <= len(sys.argv) <= 6):
print(
'USAGE: pairlon.py body1 body2 yyyy-mm-ddThh:mm:ssZ yyyy-mm-ddThh:mm:ssZ [npoints]'
)
sys.exit(1)
body1 = Body[sys.argv[1]]
body2 = Body[sys.argv[2]]
time1 = Time.Parse(sys.argv[3])
time2 = Time.Parse(sys.argv[4])
if len(sys.argv) > 5:
npoints = int(sys.argv[5])
else:
npoints = 1200
GraphPairLongitude(body1, body2, time1, time2, npoints)
sys.exit(0)
# the Earth from the Jupiter system.
#
import sys
from astronomy import Time, JupiterMoons, GeoVector, EquatorFromVector, Body, C_AUDAY
def PrintBody(name, geovec):
# Convert the geocentric vector into equatorial coordinates.
equ = EquatorFromVector(geovec)
print('{:<8s} RA {:10.6f} DEC {:10.6f} {:10.6f} AU'.format(name, equ.ra, equ.dec, equ.dist))
if __name__ == '__main__':
# If date/time is provided on the command line, use it.
# Otherwise, use the current date and time.
if len(sys.argv) == 2:
time = Time.Parse(sys.argv[1])
else:
time = Time.Now()
print('Calculations for:', time)
# Call GeoVector to calculate the geocentric position of Jupiter.
# GeoVector corrects for light travel time.
# That means it returns a vector to where Jupiter appears to be
# in the sky, when the light left Jupiter to travel toward the
# Earth to arrive here at the specified time. This is different from
# where Jupiter is at that time.
jv = GeoVector(Body.Jupiter, time, True)
# Calculate the amount of time it took light to reach the Earth from Jupiter.
# The distance to Jupiter (AU) divided by the speed of light (AU/day) = time in days.
def PrintRot(rot):
for i in range(3):
print('{:20.16f} {:20.16f} {:20.16f}'.format(rot.rot[i][0], rot.rot[i][1], rot.rot[i][2]))
if __name__ == '__main__':
# This program is a sanity check that I understand galactic coordinates.
# Compute the GAL/EQJ rotation matrix from
# the original paper at:
# https://watermark.silverchair.com/mnras121-0123.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAAqowggKmBgkqhkiG9w0BBwagggKXMIICkwIBADCCAowGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQM-h6li-3fYbw16GYKAgEQgIICXRrk54M4D9ltWJzbTRkLJ4Hb3fA4I1rbZZY7AWQlxDU7rZapZ0X7GfQWFlpffxZ-n1MULG121w6MHMZZuugksNGCqhU_8tBrNh3J1WDdLT0kig__6h72D-2ceJwydiARM-6bYd6S-z_CqScXBH6QsU8LflzPnpLz7OtfgEQQVN28ePPO2Box00NC5Sthh0Ouv06e-CyRb3ig2xP-WWP2QeGElCxJicnaDew8BUyofEHKpebe3d-Io_gXZeV7NHV1gIDTXLEp0UpM_KB9nmh39pCr4AW9zd-0j5qUlkC3TqNRlt40WuwDJn-cxFpY4O3hPtBvPmUKqspvtRP6YiqXeuCbQ6uw4OG9xcf7G39D387TeSjgGoeZRPkc0ZhpryawudLiHpXualt_uw8ws8--tAO5aUWVGL_oM2jzLEl7WVvS8jbYxXFY6GRPNBGZeDpYCP0hfXgogG305sLSWYtejlBdYECf1oJ1h_jC7HHfxI2xykD7EwI5tlRPKmNKcADJWS8Wf8zbwIE50ZB-eV1miTpBEFa6KnpD-m34k4-6dNOX9k0ALSMPOOag3o3-RGoeLdMrvqFtENM84Blo-OOADNMU5Mmo2UCjl83onZ83TdlJvSy-e2Z49i1vLScvFZlePdwJArcitb44dR1xfsbsLIR7ApcDCuF_ke96Sc3FkOOkFqM1waQZP2zuiyOr4Jg_6IFyLV5aO-2ocGoY4UkED5RzeNVSIiVC3r2QyhG51lD90ABO7LQ7RWXnsZV915Bkohh5fKIjvNM0ejAm87uMzsYhlzIIind9U6DqnCde
# Equatorial B1950.0 coordinates of the Galactic North Pole:
ra = 12.0 + 49.0/60.0
dec = +27.4
# Orientation angle for the zero lon/lat point in galactic coordinates:
theta = 123.0
# Calculate the B1950.0 epoch based on:
# https://en.wikipedia.org/wiki/Epoch_(astronomy)
b1950 = Time.FromTerrestrialTime(2433282.4235 - 2451545.0)
print('B1950 = {}'.format(b1950))
# Create a rotation matrix to convert from J2000 equatorial to B1950 equatorial.
rot = Rotation_EQJ_EQD(b1950)
# Pivot using the ra/dec angles for the galactic north pole.
rot = Pivot(rot, 2, -15*ra)
rot = Pivot(rot, 1, -(90-dec))
rot = Pivot(rot, 2, theta-180)
PrintRot(rot)