A Holistic View of the W Uma Type Ty Boo

Modern comprehensive study of the W UMa system TY Boo

“…Milone et al (1991) suggested a first spotted solution with both hot and cold spots on a cooler component, and showed that the published light curves by Carr (1972) and Samec and Bookmyer (1987) have a minimal asymmetry and can be fitted without spots. Christopoulou et al (2012) confirmed the spotted model solution suggested by Milone et al (1990) and estimated a model included two-spot model on either stellar components. They suggested that the spots were caused by cyclic magnetic activity rather than an unseen companion.…”

“…Rainger et al 1990, Milone et al 1991, and Christopoulou et al 2012 showed that the less massive, but hotter, star is eclipsed at the primary minimum. Although the light curve solution by Carr (1972) has a limited accuracy, it suggested that the system TY Boo belong to A-type systems and consists of two mainsequence components with spectral types G3 and G7 and W UMa characteristic with mass ratio of 0.88.…”

“…Our investigation shows that, the period change may be attributed to the magnetic activity. However, as shown by Stȩpień et al (2001) the X-ray flux (for the time interval 1990-1991) weaker than that of single stars, so Christopoulou et al (2012) excluded the magnetic activity as an occasion of period change. Table 7.…”

Absolute Parameters and Physical Nature of the Low-Amplitude Contact Binary Hi Draconis

“…In order to determine which model is more physically probable, we overplotted the modeled components in the massluminosity plane (Figure 6) together with other well-studied Table 9 of Christopoulou et al (2012). The lines plotted using the BSE code (Hurley et al 2002) are for the solar metallicity, ZAMS (solid line), and TAMS (dotted line).…”

“…The data are taken from the compilations of Yakut & Eggleton (2005), Li et al (2008), and Christopoulou et al (2012). As can be seen in the figure, the location of the binary components favors the general pattern of A subtype W UMa systems.…”