Long-term X-ray observations of Centaurus X-3, GX 302--2 (4U 1223--62), GX 304--1 (4U 1258--61), and 4U 1145--61

We present 7 year (1969--1976) X-ray time histories for the sources Cen X-3, GX 301--2, GX 304--1, and 4U 1145--61, with 10 day time resolution. Time series analysis confirms the 41.5 day periodicity of Gx 301-2 and adds evidence for the previously reported 187.5 day period in 4U 1145--61. A new period of 132.5 +- 0.4 days is reported for GX 304--1. Comparison of our Vela data and previous results shows that there may be a significant difference between the photometric and quoted Doppler pulse timing periods for GX 301-2. The periods of GX 301-2, GX 304--1, and 4U 1145--61 are consistent with binary orbital variations. No evidence if found for the 26.6 and 43.0 day periods previously reported for Cen X-3. The 2.087 day eclipse period of Cen X-3 appears with high significance, aliased by the detector sampling period to 20.33 days. High state activity in Cen X-3 repeats with a characteristic (but nonperiodic) timescale of 120--165 days