Studies of early-type variable stars. IX. Y Cygni.
Abstract
Absolute dimensions for the detached O-type eclipsing binary Y Cygni are derived, based on analyses of new Reticon spectra and existing photometric data. For the primary (larger) and secondary (smaller) stars respectively, we adopt the following dimensions: m/msun_=17.5+/-0.4 and 17.3+/-0.3, R/Rsun_=6.0+/-0.3 and 5.7+/-0.3, and logL/Lsun_=4.47+/-0.12 and 4.45+/-0.12. Both components are shown to have equal temperatures of 31000+/-2000K although we recognize that there remains a problem with the O star effective temperature scale and that these values may be 2000K too low. Because of this we avoided using logT_e_ in making the comparison with recent convective overshooting models. Y Cygni is a very young system, with an age of ~2-3x10^6^yr. These models also provide an apsidal motion constant logk_2_=-1.933 in excellent agreement with the observed value of -1.94+/-0.03.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- May 1995
- Bibcode:
- 1995A&A...297..127H
- Keywords:
-
- Eclipsing Binary Stars;
- O Stars;
- Stellar Evolution;
- Stellar Models;
- Stellar Spectra;
- Variable Stars;
- Astronomical Photometry;
- Radial Velocity;
- Star Formation;
- Stellar Luminosity;
- Stellar Mass;
- Stellar Temperature;
- Astronomy;
- STARS: BINARIES: ECLIPSING;
- STARS: FUNDAMENTAL PARAMETERS;
- STARS: INDIVIDUAL: Y CYG;
- STARS: EARLY-TYPE;
- STARS: VARIABLE