B,V-PHOTOMETRY OF THE RR-LYRAE STARS IN THE VERY METAL-POOR GLOBULAR-CLUSTER NGC-5053

The RR Lyrae stars in NGC 5053 are investigated using B,V photometry derived from CCD frames taken on 15 nights between 1985 and 1994. Estimates of fundamental photometric parameters are presented for the ten stars, including mean B and V magnitudes, pulsation periods, pulsation amplitudes, 〈B〉-〈V〉 colors, and period change rates. Until now the mean B,V magnitudes were unknown because the previous photographic photometry by Baade [Mitteilungen der Hamburger, Sternwarte, B6, n.29 (1928)], Sawyer [Pub. DDO 1, No. 18, p. 357 (1946)], Rosino [MSAIt, 20, 3 (1949)], and Mannino [Pub. Obs. Bologna, 8, No. 12 (1963)] is not on the Johnson system and is not readily transformed to that system.