MAXIMUM-ENTROPY MAPS OF THE BE SHELL STAR ZETA-TAURI FROM OPTICAL LONG-BASE-LINE INTERFEROMETRY

We present the. first maximum-entropy maps reconstructed from visibili ty amplitudes obtained with an optical long-baseline interferometer. T hey show the Be shell star zeta Tauri. In the continuum at 550 nm the star is an unresolved point source, whereas in the light of the Halpha line an extended, elongated structure is observed. The best-fit param eters of an elliptical Gaussian model are: major axis a = 3.55 +/- 0.3 3 mas, axial ratio r = 0.30 +/- 0.03, position angle phi = -59-degrees +/- 4-degrees. The morphology of the Halpha emission region is most e asily interpreted as a disk seen almost edge-on; if this disk is axial ly symmetric, a limit for the inclination i less-than-or-equal-to 73-d egrees can be derived. Our observations provide further evidence for t he equatorial disk model of Be stars.