And so you get all this useful information in astronomy by making the Dopplershift measurements of binary systems.
你们可以得到所有，天文学中的有用信息，只要对双星系统进行，多普勒顿移。
2
Imagine now you can make the Dopplershift measurements of both stars.
假设现在你可以，对双星进行，多普勒顿移的测量。
3
If you have a binary system whereby both stars are visible so you get the spectrum of both stars, then you see the Dopplershift of both stars in the spectrum.