1. Light from a source having a continuous Spectrum shines on a mass of Hydrogen gas. What sort of spectrum would you see if you were (a) on the opposite side of the gas from the source ? (b) off to the side ? Explain.2. Two stars have the same temperature, but the absorption lines of one are narrower than the absorption lines of the other. What could be the reason for this ? 3. An astronaut moves away from the Solar System at half the speed of light. Does the colour of the Sun change for him ? Explain.