REPORT ABUSIVE REPLY
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Message Subject
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Calling All Amateur Astronomers! How far away are stars? How do we determine this distance? What makes it reliable?
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Poster Handle
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Astronut |
Post Content
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What exactly is involved in the Cepheid variable method of measurement?
Quoting: SaveTheLivingEntitiesThe rate of fluctuation in a Cepheid variable's brightness is directly tied to its absolute luminosity, therefore monitoring the rate allows you to convert from apparent to absolute magnitude and therefore solve for distance. Quoting: AstronutExcellent descriptive answer. Absolute magnitude being solved for distance involves what sort of equation? Quoting: SaveTheLivingEntitiesYou use this formula and solve as needed: Let m = apparent magnitude Let M = absolute magnitude Let d = distance in parsecs Then m - M = -5 + 5log(d) Therefore d = 10^((m - M + 5)/5) I understand that point well. But determining the temperature of the Star doesn't directly tell us how far away a Star is, correct? It all hinges on whether or not luminosity can be correctly calculated and correlated to distance?
Quoting: saveIf you know the luminosity, then you can calculate for the distance because the apparent brightness will decrease as a function of distance as the light spreads out.
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