This paper reports on the outline and the status of the TAMA-300 project, the 300 meter laser interferometer gravitational wave detector developed by a team of scientists of several research institutes and universities in Japan. In fact the project has been funded and its construction started at the National Astronomical Observatory, Mitaka, in spring 1995. And the constructions of the tunnels for the east-west and north-south arms and of the central building are completed and a half of pipes for laser beams were brought in. Very stable laser oscillator has been almost completed and mew techniques such as vibration isolations, recycling of laser power, and suspension of mirrors by double pendulums have been developed. In fact the purposes of the project are to establish techniques necessary for future km-class detectors and to operate the detector to catch possible gravitational wave events in nearby galaxies such as Andromeda, the target sensitivity being 3 × 10-21 at 300Hz.

In attempts to detect gravitational waves, the response of some celestial systems such as the earth[l] or binary systems[2] to such waves have been investigated. Following this line of thought, here we study the possibility of excitation of the oscillation modes of a polytropic star by gravitational radiation and calculate the relevant absorption cross sections.

The rate of gravitational quadrupole radiation is derived in the formalism of source theory. It is also shown that gravitational superradiance is theoretically possible.