Gravitational Radiation from Nonaxisymmetric Instability in a Rotating Star

We present the first calculations of the gravitational radiation produced by nonaxisymmetric dynamical instability in a rapidly rotating compact star. The star deforms into a bar shape, shedding $\sim 4\mathrm{\%}$ of its mass and $\sim 17\mathrm{\%}$ of its angular momentum. The gravitational radiation is calculated in the quadrupole approximation. For a mass $M\sim 1.4$ M${}_{\odot }$ and radius $R \sim 10$km,thegravitationalwaveshavefrequency$\sim 4$kHzandamplitude$h \sim 2 \times 10^{-22}$ at the distance of the Virgo Cluster. They carry off energy $\mathrm{\Delta }E\mathrm{/}M\sim 0.1\mathrm{\%}$ and radiate angular momentum $\Delta J/J \sim 0.7%$.