B and V light curves of TY Bootis

Abstract

The short-period eclipsing binary system TY Boo was observed on five consecutive nights with the facilities at Lowell Observatory. The observations covering the eclipse portions of the light curves yielded five epochs of minimum light. A period study gives no indication of the cyclic period variation indicated by Szafraniec. The light curves, defined by 348 observations with the B filter and 353 with the V filter, are of the W Ursae Majoris type and are symmetric. The system becomes redder during each eclipse with a momentary dereddening at phase 0.0. The depths of the eclipse curves are about the same as those in the light curves published by Carr. However, the system appears to have undergone a slight reddening.

Modern comprehensive study of the W UMa system TY Boo

“…Observations by Carr (1972) in 1969 were brighter than that of Samec and Bookmyer (1987). Li et al (2005) suggested that the more massive component is brighter in 1969 than in 1986, which may cause by star spot(s) or as a result of the stellar activity.…”

“…Rainger et al (1990) combined their spectroscopic observations together with photometric observations by Samec and Bookmyer (1987) to compute the masses and absolute dimensions for the components. Their solution shows that the system TY Boo has components of G2…”

On the orbital period changes of two W-type overcontact binaries: RW Comae Berenices and CE Leonis

“…d 3034286 × E. Later, CE Leo was observed photoelectrically by Hoffmann (1983) and by Samec & Bookmyer (1987). Recently, Samec et al (1993) published complete light curves in BV RI and a photometric analysis of their observations based on the WD (Wilson-Devinney) method.…”

Photometric Observations of the Contact Binary System V523 Cassiopeiae

“…Since Weber (1958) discovered the light variability of V523 Cas, many investigations in photometry and spectroscopy have been carried out (Zhukov 1972, Haussler 1974, Lavrov & Zhukov 1975, Bradstreet 1981, Hoffmann 1981, Samec & Bookmyer 1987, Zhai et al 1988, Samec et al 1989, Kim & Jeong 2002, Samec et al 2004, Genet et al 2005, Jeong et al 2006. In results, some facts about V523 Cas are known: 1) its orbital period of about 336 minutes is one of the shortest among late type contact binaries.…”

“…Also they suggested third bodies can induce changes in eclipse epoch due to the light-travel-time effect resulting from the system shifting barycenter. Samec & Bookmyer (1987) and Samec et al (1989) reviewed the early history of this system. Mass ratios produced by photometric solutions of V523 Cas are q ph = 0.59 by Bradstreet (1981), 0.571 by Samec et al (1989), 0.53 by Lister et al (2000), 0.56 by Kim & Jeong (2002), and 0.52 by Samec et al (2004).…”