Photometric Studies of CW Cephei

Abstract

Three-filter observations of the hot, detached close binary CW Cephei are used as the basis for light curves dating to the mid-1980s. The ephemeris of apsidal rotation is improved as a result of a lengthier time base. The light-curve synthesis converges to essentially the same orbital and stellar parameters that have been accepted for almost 40 years. For the first time, emphasis is given to a new type of complication confusing the apsidal rotation behavior, and it is shown that this complication is photometric and not dynamical. In addition, we find that the light curve is itself beset by substantial complications, which may be associated with the rather feeble stellar winds.

A new photometric study of CW Cephei and its apsidal motion

“…The light curves are well represented when a small amount of (relatively red) third light (Clausen & Giménez 1991, Han et al 2002) is included. Recent parameters of the components of CW Cep were given by Correspondence to: A. Erdem, e-mail:aerdem@bornova.ege.edu.tr Han et al (2002) as M 1 =12.93 M , R 1 =5.97 R , and M 2 = 11.84 M , R 2 = 4.56 R .…”

“…e.g. Abrami & Cester 1960, Nha 1975, Clausen & Giménez 1991, Soydugan et al 2001, and Han et al 2002. These variations have been discussed in terms of weak stellar winds by Han et al (2002).…”

“…Abrami & Cester 1960, Nha 1975, Clausen & Giménez 1991, Soydugan et al 2001, and Han et al 2002. These variations have been discussed in terms of weak stellar winds by Han et al (2002). The light curves are well represented when a small amount of (relatively red) third light (Clausen & Giménez 1991, Han et al 2002) is included.…”

“…Photoelectric observations of the system were carried out by Abrami & Cester (1960), Nha (1975), Söderhjelm (1976), Han (1984), Clausen & Giménez (1991), Soydugan et al (2001) and Han et al (2002). Most light curves exhibit systematic light variations at the level of about 0.…”

An X-Ray Study of Two B+B Binaries: AH Cep and CW Cep

“…The final exposure times for the two observations were 7 ks and 10 ks for CW Cep and AH Cep, respectively. Ephemeris data from the AAVSO 2 indicates that neither system was in eclipse at the time of observation (with confirmation from Han et al (2002) for CW Cep).…”