SIMBAD references

We present CCD photometry of the eclipsing binary TW CrB. A new period and ephemerides are determined for the system based on analysis of all available times of minimum light. It is found that the orbital period of TW CrB is rapidly increasing, with a rate of dP/dt=1.54x10^–7 days/yr. A photometric solution is carried out with the Wilson-Devinney code, which reveals that TW CrB is a detached near-contact system with each of the two components almost filling its Roche lobe. Analysis of the evolutionary status of the system indicates that the primary component of the system is a main-sequence star, although slightly evolved, and the secondary is an undermassive, radially extended, and overluminous evolved star with a temperature much higher than main-sequence stars of the same mass. It is suggested that TW CrB could be a candidate with which to study the formation and evolution of contact systems.