astroconst package
Submodules
- astroconst.aa module
a_e
au
c
depsilon_dt
dj_2
domega_dt
dpsi_dt
dtheta_dut1
epsilon_j2000
g
gme
gms
gms_over_gme
j_2
kappa
l_b
l_c
l_g
m_ceres_over_m_s
m_e
m_e_over_m_m
m_m_over_m_e
m_pallas_over_m_s
m_s
m_s_over_m_eris
m_s_over_m_j
m_s_over_m_ma
m_s_over_m_me
m_s_over_m_n
m_s_over_m_p
m_s_over_m_sa
m_s_over_m_u
m_s_over_m_ve
m_sun_over_m_earthmoon
m_vesta_over_m_s
msat_over_mpl_ariel
msat_over_mpl_callisto
msat_over_mpl_europa
msat_over_mpl_ganymede
msat_over_mpl_io
msat_over_mpl_oberon
msat_over_mpl_titan
msat_over_mpl_titania
msat_over_mpl_triton
msat_over_mpl_umbriel
n
omega
one_over_f
one_over_tau_a
p_a
pi_sun
r_earth
r_jupiter
r_mars
r_mercury
r_moon
r_neptune
r_pluto
r_saturn
r_sun
r_uranus
r_venus
tau_a
tdb_0
theta_0
w_0
Module contents
AstroConst package
A Python package that provides astronomical constants. The code is being developed by Marc van der Sluys of the department of Astrophysics at the Radboud University Nijmegen, the Institute of Nuclear and High-Energy Physics (Nikhef), and the Institute for Gravitational and Subatomic Physics (GRASP) at Utrecht University, all in The Netherlands. The AstroConst package can be used under the conditions of the EUPL 1.2 licence. These pages contain the API documentation. For more information on the Python package, licence and source code, see the AstroConst GitHub page.
- astroconst.a_rad = 7.56572310579377e-16
Radiation (density) constant, 7.56591e-16 J m^-3 K^-4
- astroconst.am2r = 0.0002908882086657216
Factor to convert arcminutes to radians
- astroconst.amu = 1.66053904e-27
Atomic mass unit; (mass of C12 atom)/12, 1.6605402e-27 kg
- astroconst.as2r = 4.84813681109536e-06
Factor to convert arcseconds to radians.
- astroconst.au = 149597870700
Astronomical unit
- astroconst.au_lighttime_days = 0.005775518331436995
The light time for 1 AU in days (for apparent planet positions)
- astroconst.c = 299792458
Speed of light in vacuo
- astroconst.c2k = 273.15
Degrees Celcius to Kelvin (shift)
- astroconst.cm = 0.01
Centimeter in SI (m)
- astroconst.cos_dec_gp_2000 = 0.8899880796439262
Cosine of dec_gp_2000, needed for coordinate transformations
- astroconst.d2h = 0.06666666666666667
Factor to convert degrees to hours
- astroconst.d2r = 0.017453292519943295
Factor to convert degrees to radians.
- astroconst.day = 86400.0
Default day == solar day = 86400 s
- astroconst.day_sid = 0.997269663
Siderial day in days
- astroconst.day_sol = 86400.0
Solar day = 86400 s
- astroconst.dec_gp_2000 = 0.4734773
27.12825° in rad
- Type:
Dec of the Galactic pole for J2000
- astroconst.dow_en = array(['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'], dtype='<U9')
Capitalised day-of-week names in English.
- astroconst.dow_en_abr = array(['Sun', 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat'], dtype='<U3')
Capitalised three-letter day-of-week abbreviations in English.
- astroconst.dow_en_abr2 = array(['Su', 'Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa'], dtype='<U2')
Capitalised two-letter day-of-week abbreviations in English.
- astroconst.dow_nl = array(['zondag', 'maandag', 'dinsdag', 'woensdag', 'donderdag', 'vrijdag', 'zaterdag'], dtype='<U9')
Lower-case day-of-week names in Dutch.
- astroconst.dow_nl_abr = array(['zo', 'ma', 'di', 'wo', 'do', 'vr', 'za'], dtype='<U2')
Lower-case two-letter day-of-week abbreviations in Dutch.
- astroconst.dow_nl_abr4 = array(['zon', 'maa', 'din', 'woe', 'don', 'vrij', 'zat'], dtype='<U4')
Lower-case four-letter day-of-week abbreviations in Dutch.
- astroconst.dst_en = array(['standard time', 'daylight-savings time'], dtype='<U21')
English DST timezone names.
- astroconst.dst_nl = array(['wintertijd', 'zomertijd'], dtype='<U10')
Dutch DST timezone names.
- astroconst.eV = 1.6021766208e-19
1.6021766e-19 J
- Type:
Elementary (electron) charge in Coulomb; ElectronVolt
- astroconst.e_earth = 0.01671
//en.wikipedia.org/wiki/Orbital_eccentricity
- Type:
Orbital eccentricity of the Earth - https
- astroconst.earth_e = 0.01671
//en.wikipedia.org/wiki/Orbital_eccentricity
- Type:
Orbital eccentricity of the Earth - https
- astroconst.earth_r = 6378136.6
Equatorial radius of the Earth in SI (m), WGS84
- astroconst.ec = 1.6021766208e-19
1.6021766e-19 J
- Type:
Elementary (electron) charge in Coulomb; ElectronVolt
- astroconst.enGrChar = array(['alpha', 'beta', 'gamma', 'delta', 'epsilon', 'zeta', 'eta', 'theta', 'iota', 'kappa', 'lambda', 'mu', 'nu', 'xi', 'omicron', 'pi', 'rho', 'sigma', 'tau', 'upsilon', 'phi', 'chi', 'psi', 'omega'], dtype='<U7')
Lower-case English names for Greek characters.
- astroconst.eps0 = 0.409092599824881
Obliquity of the ecliptic in J2000.0, degrees -> radians
- astroconst.eps2000 = 0.409092599824881
Obliquity of the ecliptic at J2000.0 (radians)
- astroconst.g = 6.67428e-11
Newton’s gravitational constant
- astroconst.glon_se_2000 = 0.5747704
32.93192° in rad
- Type:
Galactic longitude of the Spring equinox for J2000
- astroconst.gr = 9.80665
Mean gravitational acceleration at the Earth’s surface, m s^-2
- astroconst.h2d = 15.0
Factor to convert hours to degrees
- astroconst.h2r = 0.2617993877991494
Factor to convert hours to radians.
- astroconst.h_bar = 1.0545718001391127e-34
Reduced Planck constant, J s
- astroconst.h_p = 6.62607004e-34
Planck’s constant, 6.6260755e-34 J s
- astroconst.htmlGrChar = array(['α', 'β', 'γ', 'δ', 'ε', 'ζ', 'η', 'θ', 'ι', 'κ', 'λ', 'μ', 'ν', 'ξ', 'ο', 'π', 'ρ', 'σ', 'τ', 'υ', 'φ', 'χ', 'ψ', 'ω'], dtype='<U9')
HTML codes for lower-case Greek characters.
- astroconst.jd1820 = 2385801
JD in 1820 (when ΔT=0)
- astroconst.jd1875 = 2405890
JD at J1875.0 (when constellation boundaries were defined)
- astroconst.jd1900 = 2415021
JD at J1900.0
- astroconst.jd1950 = 2433283
JD at J1950.0
- astroconst.jd2000 = 2451545
00 UT)
- Type:
JD at J2000.0 (2000-01-01 12
- astroconst.jd_hip = 2448349.0625
//heasarc.gsfc.nasa.gov/W3Browse/all/hipparcos.html
- Type:
JD of the Hipparcos catalogue (1991-04-02 ~13
- Type:
29 UT) - https
- astroconst.k_b = 1.38064852e-23
Boltzmann constant, 1.380658e-23 J/K
- astroconst.km = 1000.0
Kilometer in SI (m)
- astroconst.l_sun = 3.85e+26
Solar luminosity in SI (W)
- astroconst.m_h = 1.673532757988e-27
Mass of a hydrogen atom
- astroconst.m_sun = 1.9891e+30
Solar mass in SI (kg)
- astroconst.mas2r = 4.84813681109536e-09
Factor to convert milliarcseconds to radians.
- astroconst.mlen = array([31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31])
Length of the months (for non-leap year).
- astroconst.mm = 0.001
Millimeter in SI (m)
- astroconst.month = 2629748.16
Default month == Gregorian month in seconds.
- astroconst.month_ano = 2380713.1094592
apside to apside, for J2000.0.
- Type:
Anomalistic month in seconds
- astroconst.month_drac = 2351135.8785888
node to node, for J2000.0.
- Type:
Draconic month in seconds
- astroconst.month_greg = 2629748.16
average calendar month length of 4800 months over 400 years.
- Type:
Gregorian month in seconds
- astroconst.month_sid = 2360591.5576608
fixed star to fixed star, for J2000.0.
- Type:
Sidereal month in seconds
- astroconst.month_syn = 2551442.8768992
phase to phase, for J2000.0.
- Type:
Synodic month in seconds
- astroconst.month_trop = 2360584.7056224
equinox to equinox, influenced by precession, for J2000.0.
- Type:
Tropical month in seconds
- astroconst.months_en = array(['', 'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'], dtype='<U9')
Capitalised month names in English.
- astroconst.months_en_abr = array(['', 'Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'], dtype='<U3')
Capitalised month abbreviations in English.
- astroconst.months_en_abr_lc = array(['', 'jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul', 'aug', 'sep', 'oct', 'nov', 'dec'], dtype='<U3')
Lower-case month abbreviations in English.
- astroconst.months_en_lc = array(['', 'january', 'february', 'march', 'april', 'may', 'june', 'july', 'august', 'september', 'october', 'november', 'december'], dtype='<U9')
Lower-case month names in English.
- astroconst.months_nl = array(['', 'januari', 'februari', 'maart', 'april', 'mei', 'juni', 'juli', 'augustus', 'september', 'oktober', 'november', 'december'], dtype='<U9')
Lower-case month names in Dutch.
- astroconst.months_nl_abr = array(['', 'jan', 'feb', 'mrt', 'apr', 'mei', 'jun', 'jul', 'aug', 'sep', 'okt', 'nov', 'dec'], dtype='<U3')
Lower-case month abbreviations in Dutch.
- astroconst.months_nl_abr_cap = array(['', 'Jan', 'Feb', 'Mrt', 'Apr', 'Mei', 'Jun', 'Jul', 'Aug', 'Sep', 'Okt', 'Nov', 'Dec'], dtype='<U3')
Capitalised month abbreviations in Dutch.
- astroconst.months_nl_cap = array(['', 'Januari', 'Februari', 'Maart', 'April', 'Mei', 'Juni', 'Juli', 'Augustus', 'September', 'Oktober', 'November', 'December'], dtype='<U9')
Capitalised month names in Dutch.
- astroconst.moonphase_en = array(['New Moon', 'First Quarter', 'Full Moon', 'Last Quarter'], dtype='<U13')
English names of Lunar phases.
- astroconst.moonphase_nl = array(['Nieuwe Maan', 'Eerste Kwartier', 'Volle Maan', 'Laatste Kwartier'], dtype='<U16')
Dutch names of Lunar phases.
- astroconst.mum = 1e-06
Micrometer in SI (m)
- astroconst.nm = 1e-09
Nanometer in SI (m)
- astroconst.pi = 3.141592653589793
π
- astroconst.pi2 = 6.283185307179586
2π
- astroconst.pio2 = 1.5707963267948966
π/2
- astroconst.pio4 = 0.7853981633974483
π/4
- astroconst.pl_a = array([3.84400000e+08, 5.79093357e+10, 1.08204140e+11, 1.49597871e+11, 2.27942276e+11, 7.78327802e+11, 1.42698417e+12, 2.87093274e+12, 4.49706159e+12, 5.91345423e+12])
Planet semi-major axes (m); [0]=Moon
- astroconst.pl_d = array([3.47620600e+06, 4.87940000e+06, 1.21980000e+07, 1.27562732e+07, 6.79240000e+06, 1.42984000e+08, 1.20536000e+08, 5.11180000e+07, 4.95280000e+07, 2.39000000e+06])
Equatorial planet diameters (m); [0]=Moon; Venus = 12103.6km + clouds?
- astroconst.pl_e = array([0.0549 , 0.2056 , 0.0068 , 0.01671, 0.0934 , 0.0484 , 0.0541 , 0.0472 , 0.0086 , 0.2488 ])
//en.wikipedia.org/wiki/Orbital_eccentricity); [0]=Moon.
- Type:
Planet orbital eccentricities (s - https
- astroconst.pl_p = array([2.36045800e+06, 7.60035920e+06, 1.94137573e+07, 3.15569252e+07, 5.93528960e+07, 3.74328247e+08, 9.29575501e+08, 2.65142863e+09, 5.20058127e+09, 7.82422403e+09])
//en.wikipedia.org/wiki/Orbital_period); [0]=Moon.
- Type:
Planet orbital periods (s - https
- astroconst.pl_r = array([ 1738103. , 2439700. , 6099000. , 6378136.6, 3396200. , 71492000. , 60268000. , 25559000. , 24764000. , 1195000. ])
Planet equatorial radii (m) = pland/2.
- astroconst.plname_en = array(['Moon', 'Mercury', 'Venus', 'Sun', 'Mars', 'Jupiter', 'Saturn', 'Uranus', 'Neptune', 'Pluto'], dtype='<U7')
Capitalised planet names.
- astroconst.plname_en_abr = array(['Moon', 'Mer.', 'Ven.', 'Sun', 'Mars', 'Jup.', 'Sat.', 'Ura.', 'Nep.', 'Plu.'], dtype='<U4')
Capitalised planet abbreviations.
- astroconst.plname_en_lc = array(['moon', 'mercury', 'venus', 'sun', 'mars', 'jupiter', 'saturn', 'uranus', 'neptune', 'pluto'], dtype='<U7')
Lower-case planet names.
- astroconst.plname_nl = array(['Maan', 'Mercurius', 'Venus', 'Zon', 'Mars', 'Jupiter', 'Saturnus', 'Uranus', 'Neptunus', 'Pluto'], dtype='<U9')
Capitalised Dutch planet names.
- astroconst.plname_nl_abr = array(['Maan', 'Mer.', 'Ven.', 'Zon', 'Mars', 'Jup.', 'Sat.', 'Ura.', 'Nep.', 'Plu.'], dtype='<U4')
Capitalised Dutch planet abbreviations.
- astroconst.plname_nl_lc = array(['maan', 'mercurius', 'venus', 'zon', 'mars', 'jupiter', 'saturnus', 'uranus', 'neptunus', 'pluto'], dtype='<U9')
Lower-case Dutch planet names.
- astroconst.r2am = 3437.7467707849396
Factor to convert radians to arcminutes
- astroconst.r2as = 206264.80624709636
Factor to convert radians to arcseconds.
- astroconst.r2d = 57.29577951308232
Factor to convert radians to degrees.
- astroconst.r2h = 3.819718634205488
Factor to convert radians to hours.
- astroconst.r2mas = 206264806.24709636
Factor to convert radians to milliarcseconds.
- astroconst.r_earth = 6378136.6
Equatorial radius of the Earth in SI (m), WGS84
- astroconst.r_sun = 695990000.0
Solar radius in SI (m)
- astroconst.ra_gp_2000 = 3.3660329
192.85948° in rad
- Type:
RA of the Galactic pole for J2000
- astroconst.sigma = 5.6703668160832706e-08
Stefan-Boltzmann constant, 5.67051e-8 J m^-2 K^-4 s^-1
- astroconst.sin_dec_gp_2000 = 0.45598379147916696
Sine of dec_gp_2000, needed for coordinate transformations
- astroconst.sol_const = 1361.5
Solar constant in W/m^2 (Wikipedia)
- astroconst.sun_l = 3.85e+26
Solar luminosity in SI (W)
- astroconst.sun_m = 1.9891e+30
Solar mass in SI (kg)
- astroconst.sun_r = 695990000.0
Solar radius in SI (m)
- astroconst.year = 31556925.187488
Default year == tropical year (s), for J2000.0.
- astroconst.year_anom = 31558432.5386496
apside to apside, for J2000.0
- Type:
Anomalistic year in seconds
- astroconst.year_greg = 31556952.0
assumes 97 leap years in 400 years, for J2000.0
- Type:
Gregorian year in seconds
- astroconst.year_jul = 31557600.0
assumes 100 leap years in 400 years, for J2000.0
- Type:
Julian year in seconds
- astroconst.year_sid = 31558149.7676064
fixed star to fixed star, for J2000.0
- Type:
Siderial year in seconds
- astroconst.year_trop = 31556925.187488
equinox to equinox, influenced by precession, for J2000.0
- Type:
Tropical year in seconds