부산대학교 도서관

V568. Cyg has been observed photometrically, spectroscopically and photographically during a campaign on 0-B runaways. These may contain either postsupernova binaries or stars dynamically ejected. from young associations. Whereas even its variability was doubtful, we have recorded photometric minima deeper from V to U as well as strong inversion of colour indexes, the star becoming redder as the minimum gets deeper: 1986 (mean value) 1987 (mean value) July 30, 86 August 2,86 B-V - 0.26 - 0.23 + 1.74 + 1.62 U-B - 0.63 - 0.59 + 1.30 + 1.05 New transient Hα emission episodes have been observed. The equivalent widths of absorption lines of hydrogen, except Hα, change in a correlated way reaching their lowest value sometimes at photometric minima. Eclipse of a hot object with a possible disk, by a late type giant in an eccentric orbit, seems the most viable explanation. The ephemeris J.D. 2446641.5 + 152.12 days may help the search for further primary minima.