There were 105 stars in Orion OB1b and OB1d sub-association which were analyzed in this way. About 30 observations were made of each star in each of the three filters. The observations occurred near dusk and again each three hours until the stars had fallen below 2.5 airmasses. The results for all 12 stars for which periods were determined which had false alarm probabilities of less than 1% are summarized in Table 1. A comment is needed regarding two of these stars, 0101 2447 and 4771 1097. Both of these stars have periods very close to one day, thus they fill--in only a small portion of their light curves and because of the problems with the window function. However, the shape of the periodograms of these stars (see Appendix A) is consistent with Figure 3.2 and other simulations of period very close to 1 day. For this reason, I believe that FAP is very low.
