GRAVITATIONAL-RADIATION DURING THORNE-ZYTKOW OBJECT FORMATION

Calculation of gravitational radiation during binary spiralling-in lea ding to the possible formation of a Thorne-Zytkow (TZ) object (a neutr on star inside a supergiant core) is performed. The calculations were done for polytropic density distributions with different indices n, as well as for realistic models of supergiants. A maximum frequency of t he emitted gravitational waves during this process was found to range from a few to 300 initial keplerian orbital frequencies, that is from 10(-5) to similar to 0.1 Hz, depending on the model. The dimensionless strain metric amplitude can reach h similar to 10-(23.5) for a source lying 10 kpc away from the Sun. We conclude that TZ objects forming a t a rate of 1 per 500 yrs in the Galaxy could be potential astrophysic al targets for space laser intereferometers. Analysis of gravitational waveforms emitted during TZ-object formation could bring a unique inf ormation about stellar structure.