Module constants

Source

Constants§

AMU_CGS
Atomic mass unit in grams 1 AMU = 1.66053904 × 10⁻²⁷ kg = 1.66053904 × 10⁻²⁴ g
AMU_SI
Atomic mass unit (AMU) in kilograms 1 atomic mass unit = 1.66053904 × 10⁻²⁷ kg
ARCSEC_TO_RAD
Conversion factor: Arcseconds to radians 1 arcsec = π / 180 / 3600 radians
AU_CGS
Astronomical unit in centimeters 1 AU = 1.495978707 × 10¹¹ m = 1.495978707 × 10¹³ cm
AU_SI
Astronomical unit (AU) in meters 1 AU = 1.495978707 × 10¹¹ m
BOLTZMANN_CGS
Boltzmann constant in ergs per kelvin 1 erg/K = 1.38064852 × 10⁻²³ J/K × 10⁷
BOLTZMANN_SI
Boltzmann constant in joules per kelvin 1.38064852 × 10⁻²³ J/K
CITRUS_GLOBAL_EPS
A small number to avoid division by zero Used to prevent numerical errors such as division by zero
CITRUS_RT_EPS
GRAVITATIONAL_CONST_CGS
Gravitational constant in cubic centimeters per gram per second squared 6.67428 × 10⁻¹¹ m³/kg/s² = 6.67428 × 10⁻⁸ cm³/g/s²
GRAVITATIONAL_CONST_SI
Gravitational constant in cubic meters per kilogram per second squared 6.67428 × 10⁻¹¹ m³/kg/s²
HCKB
Constant: 100.0 * HPLANCK * CLIGHT / KBOLTZ Value: 1.43877735 (in appropriate units)
HPIP
Constant: HPLANCK * CLIGHT / (4.0 * PI * SPI) Value: 8.918502221e-27 (in appropriate units)
JULIAN_YEAR_SI
Length of the Julian year in seconds 365.25 days * 24 hours * 3600 seconds
LOCAL_CMB_TEMP_SI
Local mean Cosmic Microwave Background (CMB) temperature in kelvin Temperature value from Fixsen (2009): 2.72548 K
PARSEC_SI
Parsecs in meters 1 parsec ≈ 3.08567758 × 10¹⁶ m
PLANCK_CGS
Planck constant in erg seconds 1 erg = 1 × 10⁻⁷ joules
PLANCK_SI
Planck constant in joule seconds 6.626070040 × 10⁻³⁴ J·s
SOLAR_MASS_CGS
Solar mass in grams 1 Solar mass = 1.9891 × 10³⁰ kg = 1.9891 × 10³³ g
SOLAR_MASS_SI
Solar mass in kilograms 1 Solar mass = 1.9891 × 10³⁰ kg
SOLAR_RADIUS_CGS
Solar radius in centimeters 1 Solar radius = 6.957 × 10⁸ m = 6.957 × 10¹⁰ cm
SOLAR_RADIUS_SI
Solar radius in meters 1 Solar radius = 6.957 × 10⁸ m
SPEED_OF_LIGHT_CGS
Speed of light in vacuum in centimeters per second 1 c = 2.99792458 × 10⁸ m/s = 2.99792458 × 10¹⁰ cm/s
SPEED_OF_LIGHT_SI
Speed of light in vacuum in meters per second 2.99792458 × 10⁸ m/s
STEFAN_BOLTZMANN_CGS
Stefan-Boltzmann constant in erg per square centimeter per kelvin to the fourth power per second 5.670367 × 10⁻⁸ W/m²/K⁴ = 5.670367 × 10⁻⁵ erg/cm²/K⁴/s
STEFAN_BOLTZMANN_SI
Stefan-Boltzmann constant in watts per square meter per kelvin to the fourth power 5.670367 × 10⁻⁸ W/m²/K⁴
TYPICAL_ISM_DENS
Typical Interstellar Medium (ISM) density in particles per cubic centimeter A typical value for the ISM is 1000 particles/cm³