132
SOLUTION OF THE EQUATIONS
Thus, having found any pair of corresponding values of M and k we
can find k for any other star of different mass but of the same mean
density. To pass to another mean density a new quadrature is necessary.
From k we find 1 — j8 by (84-3).
Results of a number of such calculations are given in Table 13*.
Table 13.
Solution for Dense Stars ( k = 2-22.1(U 8 ).
Pc/Po
R
M
Pm^Po
©
II
V
o
¿0
O,
0-9
2-294
29-70
0-587
13-5564
0-8
1-800
8-325
0-340
13-9247
0-7
1-717
4-112
0-194
14-1289
0-6
1-790
2-592
0-1078
14-2625
0-5
1-958
1-884
0-0600
14-3549
0-4
2-223
1-483
0-0322
14-4241
0-3
2-616
1-245
0-0166
14-4748
0-0
—
0-884
—
14-5739
The values used in the calculations for this table were k = \G and
p 0 = 1. These give “stars” of mass only a few grams, but the results can
afterwards be transformed to the stellar scale. Columns 2 and 3 give the
radius in centimetres and the mass in grams resulting from the quadratures.
From these we find at once the mean density tabulated in column 4. We
can now find k for any other mass by the rule k cc M%, and the last column
contains the values of k corresponding to the sun’s mass, e.g. in the first
line, raising the mass from 29-70 gm. to 1-98.10 33 gm. involves raising k
from 2-22.HU 8 to the value shown.
If p 0 and all densities| are altered in the same ratio by altering lengths,
leaving the masses unchanged, (95-3) continues to be satisfied with the
same value of k. Hence the table is applicable for any value of p 0 , except
that the auxiliary column B should be altered in the appropriate ratio.
In practical applications of the table we are concerned only with the last
two columns.
96. As an example, let us calculate what deviation from a perfect
gas would be necessary to decrease the brightness of the sun 3 magnitudes
below that of a perfectly gaseous star of the same mass. (This is about
the difference assumed on the giant and dwarf theory.) Assume first that
k is the same for both. The reduction in L corresponding to 3 magnitudes
is in the ratio 1:16, and hence by (83-4) we must suppose 1 — /3 decreased
* Zeits. ficr Physik, 7, p. 379. The later values of the constants (Appendix i)
would increase all the entries in the last column of Table 13 by -0096.
| The previous statement that alteration of mean density involves a new
quadrature referred to problems in which p 0 is unaltered.