Constant#
- class astropy.constants.Constant(abbrev, name, value, unit, uncertainty, reference=None, system=None)[source]#
Bases:
Quantity
A physical or astronomical constant.
These objects are quantities that are meant to represent physical constants.
- Parameters:
- abbrev
str
A typical ASCII text abbreviation of the constant, generally the same as the Python variable used for this constant.
- name
str
Full constant name.
- value
numbers.Real
Constant value. Note that this should be a bare number, not a
Quantity
.- unit
str
String representation of the constant units.
- uncertainty
numbers.Real
Absolute uncertainty in constant value. Note that this should be a bare number, not a
Quantity
.- reference
str
, optional Reference where the value is taken from.
- system
str
System of units in which the constant is defined. This can be
None
when the constant’s units can be directly converted between systems.
- abbrev
Attributes Summary
A typical ASCII text abbreviation of the constant, also generally the same as the Python variable used for this constant.
If the Constant is defined in the CGS system return that instance of the constant, else convert to a Quantity in the appropriate CGS units.
The full name of the constant.
The source used for the value of this constant.
If the Constant is defined in the SI system return that instance of the constant, else convert to a Quantity in the appropriate SI units.
The system of units in which this constant is defined (typically
None
so long as the constant's units can be directly converted between systems).The known absolute uncertainty in this constant's value.
Methods Summary
Attributes Documentation
- abbrev#
A typical ASCII text abbreviation of the constant, also generally the same as the Python variable used for this constant.
- cgs#
If the Constant is defined in the CGS system return that instance of the constant, else convert to a Quantity in the appropriate CGS units.
- name#
The full name of the constant.
- reference#
The source used for the value of this constant.
- si#
If the Constant is defined in the SI system return that instance of the constant, else convert to a Quantity in the appropriate SI units.
- system#
The system of units in which this constant is defined (typically
None
so long as the constant’s units can be directly converted between systems).
- uncertainty#
The known absolute uncertainty in this constant’s value.
Methods Documentation