The Lyman-Alpha echo from the heliospheric bow shock region and its observability from earth

In first line the solar system is adapting to the counterflowing interstellar medium on the basis a magnetohydrodynamic plasma-plasma interaction. In second line then the neutral interstellar H-atoms are dynamically coupling to this resulting plasma configuration by charge exchange collisions with protons and in the region ahead of the heliopause, are piling up in density to form an H-atom wall due to the charge-exchange-induced friction with the stagnating plasma flow. Here we investigate the spectral intensity distribution of solar H-Lyman-Alpha photons resonantly backscattered from this upwind H-atom structure to the inner heliosphere. We consider the change of the solar emission profile with increasing optical thickness at growing solar distance and the thermodynamical properties of H-atoms in the wall structure in order to answer the question whether or not the Hubble Space Telescope spectrometer GHRS would be able to detect this spectral feature from the earth's orbit.