1994PASP..106.1120M

This is the second paper in a series on large-amplitude delta Scuti stars intended to determine Baade-Wesselink radii and luminosities with precision. The first paper discussed our method of analysis and its application to EH Librae; in this paper we discuss the observations and analysis of DY Herculis. Optical and infrared photometry and cross-correlated radial velocity data have been obtained and analyzed. Fourier representations for the UBVRIJHK light curves and for the radial velocity curves were used to derive a value for the minimum radius for each of sixty combinations of flux and color index. From these we adopt a mean value for the minimum radius of R_min = 2.77 ± 0.20 R_sun. When combined with effective temperatures from Breger et al. (1978), we find a mean bolometric luminosity of <L_B> = 21.70 L_sun and a mean absolute magnitude of <M_B> = 1.41. The radial excursion is 0.149 R_sun.

We use the same procedure to improve our results fro EH Librae, deriving R_min for each of 42 combinations of flux and color index, and obtain mean values of R_min = 2.62 ± 0.19 R_sun, <L_B> = 24.56 L_sun and <M_B> = 1.27.

** Tabular material from this article will appear in Vol. 3 of the AAS CD-ROM Series.