Physical Constants
The following physical constants are defined in CASA:
| Constant | Name | Value |
|---|---|---|
| pi | 3.14.. | 3.14159 |
| ee | 2.71.. | 2.71828 |
| c | speed of light | 2.99792×108 m s−1 |
| G | grav. constant | 6.67259×1011 N m2 kg−2 |
| h | Planck constant | 6.62608×10−34 J s |
| HI | HI line frequency | 1420.41 MHz |
| R | gas constant | 8.31451 J K−1 mol−1 |
| NA | Avogadro # | 6.02214×1023 mol−1 |
| e | electron charge | 8.85418782×10−12 F m-1 |
| mp | proton mass | 1.67262×10−27 kg |
| mp_me | mp/me | 1836.15 |
| mu0 | permeability vac. | 1.25664×10−6 H m−1 |
| eps0 | permittivity vac. | 1.60218×10−19 C |
| k | Boltzmann constant | 1.38066×10−23 J K−1 |
| F | Faraday constant | 96485.3 C mol−1 |
| me | electron mass | 9.10939×10−31 kg |
| re | electron radius | 2.8179e×10−15 m |
| a0 | Bohrs radius | 5.2918×10−11 m |
| R0 | solar radius | 6.9599×108 m |
| k2 | IAU grav. const2 | 0.000295912 AU3 d−2 S0−1 |