uvby light curves of the eclipsing binary system V2154 Cyg

This paper presents complete uvby light curves for the recently discovered eclipsing binary system V2154 Cyg. Additional Crawford H_beta data were also obtained. Three times of primary minima and two secondary minima are determined. An improved orbital period is found to be 2\fd6306312. A detailed photometric analysis is made using the EBOP code. This eclipsing binary is probably one of the components of a much wider double star, forming altogether a triple system. The results show that the eclipsing pair is a detached system with two late-type stars very different in size. Masses of about M_1=1.4 M_sun and M_2=0.8 M_sun are inferred for the components by using stellar evolution models. The total mass of the probable triple system is estimated to be of about 3.5 M_sun, leading to a minimum orbital period of about 140 yr for the visual pair. Table 1 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr ( 130.79.128.5)} or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/372/588