Question

Why do scientists observe blueshift in certain stars?

Answer 1

Answer:

Redshift and Blueshift Quick Check

Explanation:

1. B,C or Observer A and Observer B are moving at different speeds relative to each other.

Observer A is stationary and Observer B is moving.

2. A or when the object is moving away from the scientist

3.A or Light wave frequencies increase as an object moves toward the observer.

100% correct

Answer 2

The Doppler effect allows finding the answer for the blue shift of some stars is:

• The star closing in on us

The Doppler effect is the change in the frequency perceived by the relative movement of the emission and the receiver, in the case of light we must use relativistic relations and the expression is

            $f = f_o \sqrt{\frac{1- \frac{v}{c} }{1+ \frac{v}{c} } }$  

Where f and fo are the observed and emitted frequencies, respectively, c the speed of light and v the relative speed between the source and the observer, this speed is positive if they move away and negative if they approach.

The speed light is related to frequency and wavelength

          c = λ f

          $f = \frac{c}{ \lambda}$  

we substitute

         $\frac{1}{\lambda } = \frac{1}{lam_o } \ \sqrt{\frac{1- \frac{v}{c} }{1+ \frac{v}{c} } }$  

         $\lambda = \lambda_o \ \sqrt{ \frac{1+ \beta }{1- \beta } }$

with   $\beta = \frac{v}{c}$

The magnitude of β is always less than 1

Let's analyze the effect of the speed between the observer and the emitter on the perceived wavelength, we have two:

• The two bodies are moving away, in this case the velocity is positive, let's substitute

           $\lambda_1 = \lambda_0 \ \sqrt{\frac{1+| \beta|}{1- |\beta|} }$

We can see that the numbering of the root increases and the dominated decreases, so the root increases its value, consequently

            $\lambda_1 > \lambda_o$  

This process is called redshift.

• The two bodies are approaching, in this case the velocity is negative, we substitute

          $\lambda_2 = \lambda_o \ \sqrt{\frac{1- |\beta| }{1+ |\beta| } }$  

We see that the root decreases its value, consequently

          $\lambda_2 < \lambda_o$  

This is called the blueshift.

In this exercise, indicate that we have a blueshift, which is why the star is approaching us.

In conclusion, using the Doppler effect we can find the answer for the blue shift of some stars is:

• The star closing in on us

Learn more here: brainly.com/question/15680822