Title: Emission line variability in the optical candidate for 2A0526 – 328
Abstract: The optical candidate for the Ariel V X-ray source 2A0526 – 328 was observed with the RGO spectrograph and Image Photon Counting System of the 3.9-m Anglo-Australian telescope at dispersions of 140 and 33 Å mm–1 on three nights in 1979 February. Substantial changes were observed in the profiles and equivalent widths of the Balmer, He I and He II emission lines. High time resolution measurements at 33 Å mm–1 showed evidence of radial velocity variations consistent with a binary system period of 3–4 hr. Phase dependent variations in emission line width and strength and continuum intensity were also observed. The Hβ, Hγ and He II (λ 4686) lines were split into two components on two occasions during the high resolution observations. Several possible models for the system are discussed briefly.