( ) recently reexamined the possibility of detecting gravitational waves from exoplanets , claiming that three ultra-short period systems would be observable by LISA .
We revisit their analysis and conclude that the currently known exoplanetary systems are unlikely to be detectable , even assuming a LISA observation time T _ { obs } = 4 yrs .
Conclusive statements on the detectability of one of these systems , GP Com b , will require better knowledge of the system ’ s properties , as well as more careful modeling of both LISA ’ s response and the galactic confusion noise .
Still , the possibility of exoplanet detection with LISA is interesting enough to warrant further study , as gravitational waves could yield dynamical properties that are difficult to constrain with electromagnetic observations .