1. a) A source is moving away from an observer with a speed of 10km/s, along a path that makes a 30'' angle with the line of sight. At what wavelength with the Hα line be observed? [λ ₀ = 656.28 nm]
b) A the observer is also moving away from the source with a speed of 20km/s. along with a path that makes a 30 angle with the line of sight. At what wavelength with the Hβ line be observed?
2. If the Hα line in a source is shifted by -0.10nm. what is the radial velocity of the source?
3. For a binary s) stem with stars of equal masses in a circular orbit with a total separation r. what it the orbital speed c?
4. We observe a binary system in which the two stars are 1arcsec and 2arcsec respectively, from the center of mass. The system is 10pc from Earth. The period is 33yr. What are the masses of the two stars assuming that 90?