QQ Vir at Shanghai
Time-resolved high-resolution spectroscopy
of the pulsating sdB star   QQ Vir (PG1325+101)

John Telting et al.,   Shanghai,   July 2009
page 04
-5 -1 +1 +5

Introduction:   Pulsational line-profile variability

For rotating stars (rotational broadening > intrinsic line broadening) the Doppler-imaging principle applies: the rotation resolves the stellar disk in the velocity space of the line profile. Hence, mode-identification is 'easy'.

Pulsation modes up to L∼20 can be observed with high-resolution spectroscopy.

l=0 m=0
radial mode
l=4 m=0
zonal mode
l=5 m=-3
prograde mode
l=9 m=3
retrograde mode
l=7 m=-7
sectoral prograde