I NEED ASSIGNMENT BACK IN 3HRS IF YOU ARE NOT ABLE TO DO SO PLEASE DONT RESPND TO MY POST!!!!!!Homework based on Chap.3-4Book Discovering the Universe Ninthe Edition2. (a) Astronomical telescopes used for viewing visible light may be divided into two general classes refractors and reflectors. Describe the main component of each. (b) Which type is used by all professional astronomers and why?3.Describe the Doppler Effect and why it is of such tremendous value to astronomers.4.(a) If an object behaves as a blackbody emitter what can we learn about an object when we plot the intensity of its electromagnetic radiation vs. the wavelength (or frequency) of that radiation?(b) Why is this of interest to astronomers?5.(a) What physical process(es) produce(s) spectral lines?(b) What do you spectral lines tell us about stars?