15. A star with a continuous spectrum shines through a cool interstellar cloud composed primarily of hydrogen. The star and cloud are moving towards

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15. A star with a continuous spectrum shines through a cool interstellar cloud composed primarily ofhydrogen. The star and cloud are moving towards Earth. Which best describes the spectrum seen on Earth?AWAY?“ a. Blueshifted hydrogen emission lines“ b. Blueshifted hydrogen absorption lines“ 0. Redshifted hydrogen emission lines“ (1. Redshified hydrogen absorption lines“ ‘J 16. An astronomer wants to determine the rotation rate of a distant star. She can accomplish this byviewing the star’s spectrum and measuring“ a. How much a spectra line shifls from “redder” to “bluer” over timev b. The width of a spectral line“ 0. Either of the above“ (1. Neither of the above is measurable“