CO Cam ( TIC 160268882 ) is the second “ single-sided pulsator ” to be discovered .
These are stars where one hemisphere pulsates with a significantly higher amplitude than the other side of the star .
CO Cam is a binary star comprised of an Am \delta Sct primary star with T _ { eff } = 7070 \pm 150 K , and a spectroscopically undetected G main-sequence secondary star .
The dominant pulsating side of the primary star is centred on the L _ { 1 } point .
We have modelled the spectral energy distribution combined with radial velocities , and independently the TESS light curve combined with radial velocities .
Both of these give excellent agreement and robust system parameters for both stars .
The \delta Sct star is an oblique pulsator with at least four low radial overtone ( probably ) f modes with the pulsation axis coinciding with the tidal axis of the star , the line of apsides .
Preliminary theoretical modelling indicates that the modes must produce much larger flux perturbations near the L _ { 1 } point , although this is difficult to understand because the pulsating star does not come near to filling its Roche lobe .
More detailed models of distorted pulsating stars should be developed .
These newly discovered single-sided pulsators offer new opportunities for astrophysical inference from stars that are oblique pulsators in close binary stars .