High-dispersion time-resolved spectroscopy of the unique magnetic cataclysmic variable AE Aqr is presented .
A radial velocity analysis of the absorption lines yields K _ { 2 } = 168.7 \pm 1 km s ^ { -1 } .
Substantial deviations of the radial velocity curve from a sinusoid are interpreted in terms of intensity variations over the secondary star ’ s surface .
A complex rotational velocity curve as a function of orbital phase is detected which has a modulation frequency of twice the orbital frequency , leading to an estimate of the binary inclination angle that is close to 70 ^ { \circ } .
The minimum and maximum rotational velocities are used to indirectly derive a mass ratio of q = 0.6 and a radial velocity semi-amplitude of the white dwarf of K _ { 1 } = 101 \pm 3 km s ^ { -1 } .
We present an atmospheric temperature indicator , based on the absorption line ratio of Fe I and Cr I lines , whose variation indicates that the secondary star varies from K0 to K4 as a function of orbital phase .
The ephemeris of the system has been revised , using more than one thousand radial velocity measurements , published over nearly five decades .
From the derived radial velocity semi-amplitudes and the estimated inclination angle , we calculate that the masses of the stars are M _ { 1 } = 0.63 \pm 0.05 M _ { \odot } ; M _ { 2 } = 0.37 \pm 0.04 M _ { \odot } , and their separation is a = 2.33 \pm 0.02 R _ { \odot } .
Our analysis indicates the presence of a late-type star whose radius is larger , by a factor of nearly two , than the radius of a normal main sequence star of its mass .
Finally we discuss the possibility that the measured variations in the rotational velocity , temperature , and spectral type of the secondary star as functions of orbital phase may , like the radial velocity variations , be attributable to regions of enhanced absorption on the star ’ s surface .