Spectroscopic observations of the eclipsing Polar MN Hya ( RX J 0929 – 24 )

We present low–medium resolution optical spectroscopy of the eclipsing AM Her system MN Hya (RX J0929–24). We determine the magnetic field strength at the primary accretion region of the white dwarf to be 42MG from the spacing of cyclotron features visible during φ ∼0.4–0.7. From spectra taken during the eclipse we find that the secondary has a M3–4 spectral type. Combined with the eclipse photometry of Sekiguchi, Nakada & Bassett and an estimate of the interstellar extinction we find a distance of ∼300–700pc. We find unusual line variations at φ ∼0.9: Hα is seen in absorption and emission. This is at the same point in the orbital phase that a prominent absorption dip is seen in soft X-rays.