PHYSICAL PARAMETERS OF THE ALGOL SYSTEM TZ ERIDANI FROM SIMULTANEOUS ANALYSIS OF GENEVA 7-COLOR LIGHT CURVES

Light curves of the semi-detached eclipsing bi nary system TZ Eridani in the Geneva 7-colour photometric system were analysed using the Wils on-Devianey programme. The physical and orbital parameters have been d etermined through a self-consistent simultaneous solution of the seven light curves and of the radial velocity curves of both components. Th e following absolute elements of the components are. for the prirnary (mass gainer), M-1 = 1.97 +/- 0.06 M., R-1 = 1.69 +/- 0.03 R., M-bol = 2.36 +/- 0.09, T-eff1 = 7770 +/- 100 K, and for the secondary (mass l oser): M-2 = 0.37 +/- 0.01 M.: R-2 = 2.60 +/- 0.04 R., M-bol2 = 3 74 /- 0.13, T-eff2 = 4570 +/- 100 K. The semi-major axis A of the relativ e orbit is 10.57 +/- 0.16 R.. The regular increase of the period is de scribed. The spectral type of the components are A5/6 V (primary) and K0/1 III. The secondary has exhibited a long-term luminosity increase of about 0.06 in V between Dec. 1983 and Dec. 1996. The distance to TZ Eri is evaluated to 270 +/- 12 pc.