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Q1. If two stars have the same types of spectral lines throughout their observed

ID: 289242 • Letter: Q

Question

Q1. If two stars have the same types of spectral lines throughout their observed spectrum, what can you say is true as a consequence of this?

A. The two stars are roughly the same luminosities.  

B. The two stars are roughly the same masses.

C. The two stars are roughly the same temperatures.  

D. The two stars are roughly the same compositions.  

E. The two stars are roughly the same radii.  

A. The two stars are roughly the same luminosities.  

B. The two stars are roughly the same masses.

C. The two stars are roughly the same temperatures.  

D. The two stars are roughly the same compositions.  

E. The two stars are roughly the same radii.  

Explanation / Answer

1) C The two stars are roughly the same temperature

A spectral line may be observed either as an emission line or an absorption line. Which type of line is observed depends on the type of material and its temperature relative to another emission source

The dominant factor in the appearance of a star's spectrum is its temperature, not its composition

using temperature fact we can determine following later .

1) that most stars have similar compositions, and

2) the excitation state of the atoms in the photosphere varies with temperature.