High azimuthal number pulsation modes in fast rotating δ Scuti stars: the case of HD101158≡ V837 Cen

The frequency analysis of the line profile variations of the fast rotating (v sin i = 132 km s−1) δ Scuti star HD 101158, observed for three consecutive nights, shows the presence of two high azimuthal number non radial pulsation modes. The star is probably seen almost equator-on and both modes (νi = 12.9 c/d and ν2 = 18.5 c/d) are prograde with m = −10 and m = −14 or −15 respectively; their frequencies are different with respect to the three frequencies identified in photometric data (Poretti 1991), which probably owe due to low ` modes. Indications of the presence of these photometric modes have been found from the frequency analysis of the first two line moments. The line profile variations also show the possible presence of further modes with frequencies of 16.2, 20.3 and 21.1 c/d and small amplitudes.