The Andromeda Galaxy, M31, is the closest large spiral galaxy to our Milky Way. When we look at its chemical spectrum, we see that its hydrogen alpha emission line (Hα) has an observed wavelength of λobs = 655 nm. -Calculate z, being careful with the sign. -How fast is it moving in km/s? -Is it redshifted or blueshifted? Is it moving towards or away from us? answer to three significant figures.

The Andromeda Galaxy, M31, is the closest large spiral galaxy to our Milky Way. When we look at its chemical spectrum, we see that its hydrogen alpha emission line (Hα) has an observed wavelength of λobs = 655 nm. -Calculate z, being careful with the sign. -How fast is it moving in km/s? -Is it redshifted or blueshifted? Is it moving towards or away from us? answer to three significant figures.