Recent changes in the absorption spectrum of 17 Leporis.

The spectroscopic binary i7 Leporis is shown to undergo profound changes in the character of its absorption spectrum. In 1925 and again in 1928-1929 the spectrum con- tained many strong lines of Ti ii, Fe ii, Sc ii, H, and weaker lines of Mg n, Fe i, and of other elements. Recent plates taken in October, 1930, show no lines of Fe i. The lines of Sc II and of Ti u are greatly weakened, while those of FeII are weakened in a smaller degree. The lines of Mg it and of H have not changed appreciably. Many of the strong- er lines appear as close doubles on the recent plates. The hydrogen lines are peculiar. The radial velocity derived from the Mg u line differs from that derived from the other lines