(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

The Galactic Cepheid variable δ Cephei has a parallax of 0.0033 arcseconds. An astronomer locates another Cepheid, with the same period as δ Cephei, in the Small Magellanic Cloud (SMC). If this Cepheid appears 11.5 magnitudes fainter than δ Cephei, calculate the distance to the SMC.

2. Relevant equations

[tex]m-M=5\log(d)-5[/tex]

[tex]L=4\pi R^2F[/tex]

[tex]m_{1}-m_{2}=2.5\log( L_{2}/L_{1})[/tex]

3. The attempt at a solution

Well, I know the distance to the first Cepheid, as it is 1/Parallax = 303pc. I understand that the same period means the same luminosity, and that 11.5 fainter will mean that the m will be actually 11.5 larger, But I'm unsure how this will help me. Unless you say that [tex]m_{1}-m_{2}[/tex] is 11.5 and change the L's for 1/d^2 ?

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# Homework Help: Cepheid Variables and the Small Magellanic Cud

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