A Popular History of Astronomy During the Nineteenth Century / Fourth Edition

by Agnes M. Clerke

[1436] Phil. Trans., vol. clviii., p. 529.

[1437] Schellen, Die Spectralanalyse, Bd. ii., p. 326 (ed. 1883).

[1438] Proc. Roy. Soc., vol. xx., p. 386.

[1439] System of the Stars, p. 199.

[1440] Pickering, Am. Jour. of Sc., vol. xxxix., p. 46; Vogel, Astr. Nach. No. 3,017.

[1441] Sitzungsberichte, Berlin, May 2, 1901; Astroph. Jour., vol. xiii., p. 324.

[1442] The "relative orbit" of a double star is that described by one round the other as a fixed point. Micrometrical measures are always thus executed. But in reality both stars move in opposite directions, and at rates inversely as their masses round their common centre of gravity.

[1443] Vogel, Astr. Nach., Nos. 3,017, 3,039.

[1444] Huggins, Pres. Address, 1891; Cornu, Sur la Méthode Doppler-Fizeau p. D. 38.

[1445] Sitzungsb., Berlin, 1890, p. 401; Astr. Nach., No. 2,995.