Astron. Astrophys. Suppl. Ser. 138, 11-18

Determination of physical parameters of five large amplitude $\delta$ Scuti stars

J.H. Peña, D. González, and R. Peniche

Send offprint request: J.H. Peña

Instituto de Astronomía, UNAM, Mexico Apartado Postal 70-264, D.F., Mexico

Received December 30, 1997; accepted March 1, 1999

Abstract:

$uvby-\beta$ photometry of the large amplitude $\delta$ Scuti stars BP Peg, DY Peg, DY Her, CY Aqr and YZ Boo is presented. Since the data were obtained almost simultaneously in all filters, meaningful physical parameters have been derived for each star along their pulsation cycles using the calibrations from Nissen (1988) for A and F stars to determine the reddening and derive the unreddened photometric values. The utilization of the theoretical grids of Relyea & Kurucz (1978) has allowed temperature and gravity values to be determined. A comparison with previously reported values is presented.

Key words: stars: fundamental parameters -- $\delta$ Sct