# -*- coding: utf-8 -*-
"""
Contains astronomical and physical constants in cgs units (for unit conversion, see astro.units).
"""
Msun = 1.9891e33         # the mass of the Sun, in g
Lsun = 3.84e33           # the luminosity of the Sun, in erg
Rsun = 6.551e10          # the radius of the Sun, in cm
Tsun = 5777.             # the effective temperature of the Sun, in K

Mearth = 5.9736e27       # the mass of the Earth, in g
Rearth = 6.378136e8      # the radius of the Earth along the Equator, in cm

G = 6.673e-8             # the gravitational constant, in cm³·g⁻¹·s⁻²
c = 2.99792458e10        # the speed of light, in cm·s⁻¹

h = 6.626069e-27         # Planck's constant, in erg·s
k = 1.38065e-16          # Boltzmann's constant, in erg·K⁻¹
sigma = 5.6704e-5        # Stefan-Boltzmann's constant, in erg·s⁻¹·cm⁻²·K⁻⁴
a = 4 * sigma / c        # the radiation constant, in erg·cm⁻³·K⁻⁴

amu = 1.6605387e-24      # Atomic mass unit, in g
me = 9.109382e-28        # the mass of the electron, in g
mp = 1.6726216e-24       # the mass of the proton, in g
mn = 1.6749272e-24       # the mass of the neutron, in g
mH = 1.6735325e-24       # the mass of the Hydrogen atom, in g

NA = 6.022142e23         # Avogadro's number, in mol⁻¹
R = 8.31447e7            # Gas constant, in erg
a0 = 5.2917721e-9        # Bohr radius in cm
Ry = 1.09737315685e9     # Rydberg constant in cm⁻¹

sigmaT = 6.6524586e-25   # Thomson cross section in cm⁻²
