Eddington による恒星間空間の平衡温度に関する記載の引用です。

この本はアマゾンなどで購入が可能ですので興味のある方は是非原著を見てください。。

なるべく忠実に再現したので現在の表記方法とは異なるところもあるので注意してください。

The internal constitution of the stars

by Arthurs S. Eddington

Cambridge University Press

First published 1926

Reissued in the Cambridge Science Classics series 1988

p.371

CHAPTER XIII

DIFFUSE MATTER IN SPACE

The Temperature of Space

256. The total light received by us from the stars is estimated to be
equivalent to about 1000 stars of the first magnitude. Allowing an average
correction to reduce visual to bolometric magnitude for stars of types
other than F and G, the heat received from the stars may be taken to correspond
to 2000 stars of apparent bolometric magnitude 1･0. We shall first calculate
the energy-density of this radiation,

A star of absolute bolometric magnitude 1･0 radiates 36･3 times as much
energy as the sun or 1･37.10^{35} ergs per sec. This gives 1･15.10^{-5} ergs per sq.cm.per sec. over a sphere of 10 parsecs(3･08.10^{19}cm.)radius. The corresponding energy-density is obtained by dividing by
the velosity of propagation and amounts to 3･83.10^{-16 }ergs per cu.cm. At 10 parsecs distance the apparent magnitude is equal
to the absolute magnitude; hence the energy-density 3･83.10^{-16} corresponds to apparent bolometric magnitude 1･0.

Accordingly the total radiation of the stars has an energy-density

2000 × 3･83.10^{-16} = 7･67.10^{-13} ergs/cm.^{3}

By the formula E = αT^{4} the effective temperature corresponding to this density is

3°･18 absolute

In a region of space not in the neighbourhood of any star this constitutes
the whole field of radiation, and a black body, e.g. a black bulb thermometer,
will there take up a temperature of 3°･18 so that its emission may balance
the radiation falling on it and absorbed by it. This is sometimes called
the "temperature of intersteller space."