Question

From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 486.1 nanometers (nm). The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 485.9 nm. What can we conclude

Answer 1

We conclude that star moving toward observer.

Step-by-step explanation:

According to the theory of doppler effect of light.

There are two kind of shift 1 ) Blue shift 2 ) Red shift, in which

1 ) if source of light moving toward observer so the apparent frequency of light increase( wavelength decrease ). This is which we call blue shift

2 ) if the distance between source and observer is increase, so the apparent frequency of light decrease ( wavelength increase ). This is which we call red shift.

Here, in our case wavelength of H-star is decrease so we can say that star moving toward observer ( Blue shift ).