Studies of Large-Amplitude Delta Scuti Variables. II. DY Herculis
Abstract
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. (SECTION: Stars)
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- November 1994
- DOI:
- 10.1086/133488
- Bibcode:
- 1994PASP..106.1120M
- Keywords:
-
- Radial Velocity;
- Radii;
- Stellar Luminosity;
- Stellar Magnitude;
- Stellar Spectrophotometry;
- Stellar Temperature;
- Variable Stars;
- Color;
- Data Reduction;
- Flux Density;
- Infrared Photometry;
- Light Curve;
- Visual Photometry;
- Astronomy;
- DELTA SCUTI;
- STARS: FUNDAMENTAL PARAMETERS