•Q5:
You identify the Balmer series absorption lines in the spectrum of a hot
type O star, but notice that the lines are shifted from their laboratory
wavelengths. For instance, H-beta, normally seen at 486 nm
appears at 488 nm. What can you deduce about the motion of this star
relative to Earth? USE THE DOPPLER EQ:
–v/c = (λobs/λrest)
– 1;
–v/c = (488/486) – 1 =
0.004115
–V = 0.004 x 300,000 km/s = 1200 km/s toward us