New Radial Velocity Observations Of Ah Her: Evidence For Material Outside The Tidal Radius

Spectroscopic observations of AH Herculis during a deep quiescent state are put forward. We found the object in a rare long minima, allowing us to derive accurately the semi-amplitudes: K-1 = 121 +/- 4 km s(-1) and K-2 = 152 +/- 2 km s(-1) and its mass functions M(W)sin (3)i = 0.30 +/- 0.01 M-circle dot and M(R)sin (3)i = 0.24 +/- 0.02M(circle dot), while its binary separation is given by asin i = 1.39 +/- 0.02 R-circle dot. The orbital period P-orb = 0.25812 +/- 0.00032 d was found from a power spectrum analysis of the radial velocities of the secondary star. These values are consistent with those determined by Horne, Wade & Szkody. Our observations indicate that K5 is the most likely spectral type of the secondary. We discuss why we favour the assumption that the donor in AH Her is a slightly evolved star, in which case we find that the best solution for the inclination yields i = 48 degrees +/- 2 degrees. None the less, should the donor be a ZAMS star, we obtain that the inclination is between i = 43 degrees and i = 44 degrees. We also present Doppler tomography of H alpha and H beta, and found that the emission in both lines is concentrated in a large asymmetric region at low velocities, but at an opposite position to the secondary star, outside the tidal radius and therefore at an unstable position. We also analyse the H alpha and H beta line profiles, which show a single broad peak and compare it with the previous quiescent state study that shows a double-peaked profile, providing evidence for its transient nature.