A New Variable in M 25

As part of the programs for infrared photometry of cepheids and for the study of interstellar extinction, Dr. W. Wis'niewski and I have reobserved a few stars in M 25. Table I lists all the UBV photometry, old and new, on stars Nos. 50, 91, and 150, as identified on Johnsons (1960) chart. Columns as labeled give V, (BV), (17B), and the number of observations for each star; an approximate Julian Date is given, and the source of the data is indicated. Irwin's data were communicated to Johnson in 1957, and 70 stars in common with Johnson (1960) were used to transform Irwin's instrumental system to Johnson's M 25 magnitude scale. Sandage's (1960) data were corrected as indicated by Mitchell, Johnson, and Iriarte (1961). The data by Wampler, Pesch, Hiltner, and Kraft (1961) were corrected to Johnson's system on the basis of data presented by Landolt (1964) in his comparison of Irwin's data, reduced to the Cape BV system, with other M 25 photoelectric studies. The corrections added to WPHK data are AV = -0.20, A(BV) = +0*006 0.030 (BV). No regional corrections have been applied to the new Catalina observations as given in Table I. Stars No. 91 and No. 150 were used as comparison stars for No. 50. For each Julian Day entry in Table I, the means of the zeropoint corrections for No. 91 and No. 150 were added to the magnitude and color indices of star No. 50 with the results shown in