Name ____________________________ID#______________________________Section____________________________Stars and the H-R Diagram Pre-labHand in this pre-lab at the beginning of the Stars and the H-R Diagram Lab.Reading: The Essential Cosmic Perspective, Sections 5.2 and 11.1, and pages 292-293 or A Beginner’s Guide to the Universe, Sections 2.4 and 10.1 – 10.5.Much of what we know about the Universe is based on what we know about stars. Our knowledge of light and spectra enables us to study the properties of stars without being able to visit them directly. In this lab, we’ll look at how we use the information contained in starlight to determine their sizes, temperatures, distances and luminosities.Recall from lecture and Chapter 2 that the color of light depends upon its wavelength. Rank the following “colors” of light from 1 to 9 in order of increasing wavelength:green____ infrared____ orange____ yellow____ red____ultraviolet____ microwave____ x-ray____ blue____In the Light & Spectra Lab, you observed the thermal spectrum of a hot (~3000K) light bulb filament and saw a full “rainbow” of colors. Figure 5.10 in Bennett or Figure 2.10 in Chaisson shows graphs of the spectrum of objects of various temperatures – notice the rainbow is only a small part of the spectrum.Imagine you were observing the objects that created the curves in Figure 2.10. How could you use filters to tell which object is which?rev. 092506In the Light & Spectra Lab, you saw that mixing light of pure colors in various combinations causes our eye to perceive “combination” colors like magenta (red light plus blue light) or cyan (blue light plus green light). Look carefully at Figure 5.10 (Bennett) or Figure 2.10 (Chaisson) – there is a narrow range of wavelengths labeled “visible spectrum.” The text notes that hotter objects emit photons with shorter average wavelength. Use the graphs in the figure to explain why thelight of a 60,000K star looks blue and the light of a 600K star looks red to the naked eye.Capella is a yellow star in the chariot of Auriga, Mimosa is a blue star in the famous Southern Cross, and Ross 248 is a nearby red star. Rank these three stars in order of surface temperature, and briefly explain your reasoning.hottest ____________________________middle____________________________coolest