Summary of the Origin of Nonradiative Heating/momentum in Hot Stars

Nonradiative heating in the atmospheres of stars and the deposit of nonradiative momentum in the stellar atmosphere were examined. Observations made from space have been very important in changing the concept of what a star is like. In order to interpret the spectroscopic information gained in the wavelength region inaccessible from the surface of the Earth, chiefly in the domain of X-rays and of ultraviolet radiation. The assumptions which underlie the theory of stellar atmospheres will have to be reused. Improved observation facilities are major reasons to consider new ideas for interpreting the spectra of stars. The photometric precision and sensitivity for observing at high and at moderate spectral resolutions have increased greatly. The development of high dispersion, high resolution spectrographs for observing is noted.