Symbol
Meaning
Typical unit
Introducing
equation
F gss
Perturbations arising from other massive
objects in the Solar System
[N]
4.124
f i
Ionization frequencies for electron impacts
with water molecules
[s
À1
]
5.11
F i
Recoil force acting on the i
th facet of a body [N]
1.24
f ice
Mass fraction of ice
2.120
F N
Emitted thermal flux from a resolved surface [W m
À2
]
2.124
F N
Reflected flux from unresolved nucleus in
visible wavelength
[W m
À2
] or
[W m
À2 nm
À1
]
2.1
f osc
Oscillator strength for a particular transition
3.119
f ph
Photo-ionization frequency
5.34
F pr
Radiation pressure force
[N]
4.67
F r , F t
Radial and transverse forces acting on the
nucleus
[N]
1.23
F ref
The reflected flux from an unresolved
nucleus seen by an observer
[W m
À2
]
2.6
f k T
,ph
Photo-ionization frequency for species k T
5.6
f tan
Effective tangential fraction of the theoretical volatile flux at zero solar phase angle that
contributes to a net torque
Unitless
2.35
F th
Thermal flux from an unresolved isothermal
object
[W m
À2
]
2.13
F vdW
Van der Waals force
[J]
4.95
f vol
Factor that defines escaping volatile content
of dust
4.127
g
Gravitational acceleration
[m s
À2 ]
2.129
g(r h )
Function intended to account for variation of
outgassing strength with heliocentric
distance
Unitless
1.22
G d
Integral of the dust column density on a
circle about a point source
[kg m
À1
]
4.3
g f
Band emission rate
[photon s
À1
molecule
À1
]
3.38
G g,c,s
Products of the impact parameter and the
integral of the column density on a circle
multiplied by variables to produce invariant
values in the free radial expansion
approximation
3.5–3.7
GM
Geopotential of an object
[m
3 s
À2
]
(1)
h
Planck’s constant
[J s]
2.8
h e
Specific enthalpy
3.58
H
Hamaker constant
[J]
4.95
H(μ, μ 0 )
Functions within the Hapke formalism for
reflectance
2.66
(continued)
xxvi
Symbols Used
Meaning
Typical unit
Introducing
equation
F gss
Perturbations arising from other massive
objects in the Solar System
[N]
4.124
f i
Ionization frequencies for electron impacts
with water molecules
[s
À1
]
5.11
F i
Recoil force acting on the i
th facet of a body [N]
1.24
f ice
Mass fraction of ice
2.120
F N
Emitted thermal flux from a resolved surface [W m
À2
]
2.124
F N
Reflected flux from unresolved nucleus in
visible wavelength
[W m
À2
] or
[W m
À2 nm
À1
]
2.1
f osc
Oscillator strength for a particular transition
3.119
f ph
Photo-ionization frequency
5.34
F pr
Radiation pressure force
[N]
4.67
F r , F t
Radial and transverse forces acting on the
nucleus
[N]
1.23
F ref
The reflected flux from an unresolved
nucleus seen by an observer
[W m
À2
]
2.6
f k T
,ph
Photo-ionization frequency for species k T
5.6
f tan
Effective tangential fraction of the theoretical volatile flux at zero solar phase angle that
contributes to a net torque
Unitless
2.35
F th
Thermal flux from an unresolved isothermal
object
[W m
À2
]
2.13
F vdW
Van der Waals force
[J]
4.95
f vol
Factor that defines escaping volatile content
of dust
4.127
g
Gravitational acceleration
[m s
À2 ]
2.129
g(r h )
Function intended to account for variation of
outgassing strength with heliocentric
distance
Unitless
1.22
G d
Integral of the dust column density on a
circle about a point source
[kg m
À1
]
4.3
g f
Band emission rate
[photon s
À1
molecule
À1
]
3.38
G g,c,s
Products of the impact parameter and the
integral of the column density on a circle
multiplied by variables to produce invariant
values in the free radial expansion
approximation
3.5–3.7
GM
Geopotential of an object
[m
3 s
À2
]
(1)
h
Planck’s constant
[J s]
2.8
h e
Specific enthalpy
3.58
H
Hamaker constant
[J]
4.95
H(μ, μ 0 )
Functions within the Hapke formalism for
reflectance
2.66
(continued)
xxvi
Symbols Used