Distance to stars

Distance to stars

Measure intensity through observation

Intensity = luminosity/4πD2

Measure λmax through observation

Wien’s Law      λmax=b/T    (b=displacement constant = 2.897 7685 × 10–3 m K)

Calculate surface temperature of star

Stefan-Boltzmann law      luminosity = σT4 (σ= Stefan-Boltzmann constant = 5.670 4×10−8 W•m-2•K-4)

Therefore (re-arrange first equation) 4πD2 = luminosity / intensity
D=distance to star


try it. i doubt it comes up with 3000 miles.

and a slightly easier way to do it at home:
http://www.exploratorium.edu/snacks/solar_brightness/index.html

"The distance to the sun is 1.5 x 10^11 m."

Neat ... but how can we trust the constants b and σ or the laws themselves?

well, Wien's Law works just fine with lightbulbs.

but star's are a big bigger then lightbulbs, and wouldnt the consistancy and size of the object, and that fact that its burning something completely different then anything here on earth dismay the results a bit?

but star's are a big bigger then lightbulbs, and wouldnt the consistancy and size of the object, and that fact that its burning something completely different then anything here on earth dismay the results a bit?

look at the fucking law, for fucks sake. it involves the median emitted wavelength and temperature. not mass or size or anything else.