ASTR220 Hamilton Homework #3 (12 points) due Wednesday Apr. 8 at the beginning of class 1. Describe what will happen to the Earth as the Sun evolves into a red giant star. 2. How does the evolution of a massive star (20 solar masses) differ from the evolution of our Sun? Describe and account for the differences. 3. Astronomers believe that they have detected several good black hole candidates. How can this be possible if black holes emit no light? Describe. 4. What forces support a sun-like star against gravitational collapse? What forces support a white dwarf against collapse? What forces support a neutron star against collapse? Use your answers to these question to describe what happens as you slowly pile mass onto a neutron star. 5. Given the following information for a star answer each question and give reasons behind your answers: A. The spectrum of a star is scanned and peak wavelength is determined to be 10,000 Angstroms. What is the star's approximate temperature? B. A star is found that has a spectrum nearly identical to the Sun (same spectral features and line strengths). Give 2 properties of this star. C. Given the spectrum below, in which all spectral lines are shifted toward longer wavelengths, what would you conclude about the star? spectral lines Our Sun: shorter longer wavelengths | | | ||| | wavelengths The Star: shorter longer wavelengths | | | ||| | wavelengths