OPTICAL FLUCTUATIONS OF SCORPIUS-X-I

The light output from Sco X- I was sampled at intervals of I ms, 10 ms and 10 s in 1972 June. The optical fluctuations were essentially random in the range of periods from 4 to 320 ms while in the period range from 20 to 256 s a significant periodic oscillation at (120.5±1.2) s persisted during four successive nights. This period corresponded to an oscillation of Sco X- I reported earlier. During one night the light output decreased by half in 25 m; during this decrease the period of the oscillation changed to (118.3±0.8) s. © Royal Astronomical Society