Astromony question

  • Thread starter asdf1
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  • #1
asdf1
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There's an astromony question that I'm stuck on~
" A distant galaxy in the constellation Hydra is receding from the Earth at 6.12*10^7 m/s. By how much is a green spectral line of wavelength 500nm (1nm=10^(-9) )emitted by this galaxy shifted toward the red end of the spectrum?
 

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  • #2
neurocomp2003
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what knowledge do you have?
 
  • #3
Andrew Mason
Science Advisor
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asdf1 said:
There's an astromony question that I'm stuck on~
" A distant galaxy in the constellation Hydra is receding from the Earth at 6.12*10^7 m/s. By how much is a green spectral line of wavelength 500nm (1nm=10^(-9) )emitted by this galaxy shifted toward the red end of the spectrum?

Just use the relativistic doppler effect:

[tex]\nu_{obs}/\nu_{source} = \sqrt{\frac{1+\beta}{1-\beta}}[/tex]

where [itex]\beta = v/c = .204[/itex] and [itex]\nu_{source} = c/\lambda_{source}[/itex]

AM
 
  • #4
asdf1
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How did you think of to use the Doppler effect?
 
  • #5
Nylex
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Probably because the question is about the Doppler effect (well, it's about red shift, which is to do with the Doppler effect). Also, you mean "astronomy", not "astromony".
 
  • #6
asdf1
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I see~
Thanks for correcting my spelling mistake!
 

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