Q20DQ
Question
Stars other than our sun normally appear featureless when viewed through telescopes. Yet astronomers can readily use the light from these stars to determine that they are rotating and even measure the speed of their surface. How do you think they can do this?
Step-by-Step Solution
Verified Answer
There is a Doppler shift for the light which is used to calculate the rotation speed.
1Step1: Explanation
As the star rotates, assuming its axis doesn’t point straight at the Earth, one side moves away from us and the other side moves toward us. This shifts the received light toward longer and shorter wavelengths, respectively (so-called redshifts and blueshifts).
From the size of these shifts, astronomers infer the tangential speed of the rotating star, and from that, deduce the rotational speed.
Other exercises in this chapter
Q17DQ
A large church has part of the organ in the front of the church and part in the back. A person walking rapidly down the aisle while both segments are playing at
View solution Q19DQ
Can you think of circumstances in which a Doppler effect would be observed for surface waves in water? For elastic waves propagating in a body of water deep bel
View solution Q21DQ
If you wait at a railroad crossing as a train approach and passes, you hear a Doppler shift in its sound. But if you listen closely, you hear that the change in
View solution Q22DQ
In case 1, a source of sound approaches a stationary observer at speed u. In case 2, the observer moves toward the stationary source at the same speed u. If the
View solution