Homework 1 Solutions

Same as above but with t 293 k 836 w or 08 kw net

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Unformatted text preview: spectrum is this found? Wein’s displacement law: λpkT ≈ 3000 µm ­K => λpk = 0.022 µm = 22 nm – this is in the UV (d) [10 pts] What is its radiant flux at the surface of the Earth? How does this compare to the Sun’s radiant flux at the surface of the Earth? (in both cases, ignore scattering and absorption from our atmosphere) radiant flux = L/4πd2 = (200 x 3.9x1026 W)/(4π x 440 pc x 3.1x1016 m/pc)2 = 3.3x10 ­11 W/m2 The sun’s radiant flux on the Earth is about 1360 W/m2, so PG 1159 ­ 035 is 14 orders of magnitude fainter! (e) [5 pts] What kind of star is PG 1159 ­035? (justify your answer based on the properties above; do not just look it up!) It is a hot star but has a very small radius, so this is probably a very recently emerged white dwarf (core of a dead star) (6) Staying Warm Out There [30...
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This document was uploaded on 02/26/2014 for the course PHYS 160 at UCSD.

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