If a Galaxy Has a Recessional Velocity of 50,000 Km/s $\alpha$

question 93

Multiple Choice

If a galaxy has a recessional velocity of 50,000 km/s, at what wavelength will you observe the H $\alpha$ emission line? (Note that the rest wavelength of the H $\alpha$ emission line is 656.3 nm.)

• A) 695.7 nm
• B) 719.4 nm
• C) 742.3 nm
• D) 765.7 nm
• E) 1,750 nm

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