Stellar atmospheres : $b A contribution to the observational study of high temperature in the reversing layers of starsPayne-Gaposchkin, Cecilia
Science
Stellar atmospheres : $b A contribution to the observational study of high temperature in the reversing layers of stars
Payne-Gaposchkin, Cecilia
Astrophysics; Stars -- Spectra; Stars -- Temperature; Thesis (Ph. D.)
71
Lu
2
4
4
6
6
6
8
8
8
8
4
4
1
-
-
(2)
72
Hf
2
4
4
6
6
6
8
8
8
8
4
4
2
-
-
(2)
79
Au
2
4
4
6
6
6
8
8
8
8
6
6
6
-
-
1
80
Hg
2
4
4
6
6
6
8
8
8
8
6
6
6
-
-
2
81
Ti
2
4
4
6
6
6
8
8
8
8
6
6
6
-
-
2
1
82
Pb
2
4
4
6
6
6
8
8
8
8
6
6
6
-
-
(4)
83
Bi
2
4
4
6
6
6
8
8
8
8
6
6
6
-
-
4
1
86
Rd
2
4
4
6
6
6
8
8
8
8
6
6
6
-
-
4
4
88
Ra
2
4
4
6
6
6
8
8
8
8
6
6
6
-
-
4
4
-
-
-
-
2
89
Ac
2
4
4
6
6
6
8
8
8
8
6
6
6
-
-
4
4
1
-
-
-
(2)
90
Th
2
4
4
6
6
6
8
8
8
8
6
6
6
-
-
4
4
2
-
-
-
(2)
118
?
2
4
4
6
6
6
8
8
8
8
8
8
8
8
-
6
6
6
-
-
-
4
4
The table also gives the number of spectroscopic valency electrons,
a quantity which is required by the theory of thermal ionization.
The spectroscopic valency electrons are those in equivalent outer
orbits (outer orbits of equal total quantum number which have the
same azimuthal quantum number). The number is not necessarily the same
as the number of chemical valencies (the number of orbits with the same
total quantum number) although the two values coincide for the
alkali metals and for the alkaline earths. For carbon,[6] on the other
[Pg 11]
hand, the number of spectroscopic valency electrons is two (the number
of 22 orbits), while the chemical valency, corresponding to the total
number of 2-quantum orbits, is four.
THE PRODUCTION OF LINE SPECTRA
It is not proposed to discuss the theory of the origin of line spectra
here in any detail. What is important from the astrophysical point of
view is the association of known lines in the spectrum with different
levels of energy in the atom, these levels representing definite
electron orbits. Absorption and emission of energy take place in an
atom by the transfer of an electron from an orbit associated with low
energy to an orbit associated with high energy, and vice versa. The
frequency of the light which is thus absorbed or emitted is expressed
by the familiar quantum relation:
where and are the initial and final energies,
, and
is the frequency of the light absorbed or given out.
The atom absorbs from its environment the quanta relevant to the
particular electron transfers of which it is capable at the time. These
transfers are, of course, governed by the number and arrangement of the
spectroscopic valency electrons, or in other words, by the state of
ionization or excitation of the atom.
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