AA) A galaxy with diameter 6.2 Mega parsec has an observed 388.5 nm spectral line, that usually corresponds to a 393/3 nm line. Use Doppler shift (blue or red?) to determine the speed (towards or away from Earth) of this galaxy and calculate how much time this galaxy had been expanding (or contracting).

ZZ) Briefly discuss the evolution of Binary Stars. Use the terms: Roche Lobe.....Lagrange points....mass exchange....and any other term you think important to your answer.