Аннотация:An intensive monitoring campaign aimed at detecting rotation periods in a set of bright T Tauri and Herbig Ae/Be stars was undertaken during the 1985/86 Milky Way season. Between 85 and 200 V magnitude measurements were made for each star on the program. In addition to the rotation period found for T Tau, on the basis of these data (Herbst et al. 1986) we find a probable period for SU Aur of 1.55 or 2.73 ± 0.03 days, the ambiguity arising because of a sampling frequency of (1 day)-1, and a possible period for RY Tau of 5.6 days. Z CMa displayed a remarkably regular variation of peculiar form on a time scale of 60 days, which could be its rotation period. Our study suggests that periodicity due to rotational modulation may be present in all T Tauri light curves, but that it will often be difficult to find due to masking by large-amplitude, irregular variations. Significant peaks in the periodograms of all the large-amplitude variables in our sample are seen at periods of 30-70 days. RY Tau has shown a persistent periodicity of about 65 days during the last three seasons. This cannot be its rotation period. Other aspects of the variability of these stars are discussed, and absolute photometry given for comparison and check stars.