GK
THE UNIVERSE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Stellar Parallax
|
|
|
Standard Candles
|
|
|
Doppler Shift (Red Shift)
|
|
|
None of the above
|
Detailed explanation-1: -Because the change in wavelength is directly related to relative speed, astronomers can use Doppler shift to calculate exactly how fast an object is moving toward or away from us. Astronomers can also track the Doppler shift of a star over time to estimate the mass of the planet orbiting it.
Detailed explanation-2: -Doppler shifts arise from the relative motion of source and observer through space, whereas astronomical redshifts are ‘expansion redshifts’ due to the expansion of space itself. Two objects can actually be stationary in space and still experience a red shift if the intervening space itself is expanding.
Detailed explanation-3: -When an object is moving away from us, the light from the object is known as redshift, and when an object is moving towards us, the light from the object is known as blueshift.