Stellar parameters HW - magnitudes because both can look as...

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Andrzej Maslonka 2/24/09 Stellar Parameters HW 1. a) d=B/p d(earth)=1/.01=100 d(Hipparchos)=1/.0014=714 Hipparchos can probe around seven times farther. b) What does the number of stars measured in both cases tell us about the shape of our galaxy? 2 . L=4(3.14)r^2(S)=4(3.14)(1.496*10^11)^2(1.37*10^3)=3.85*10^26 4. The parallax would be based on a larger distance. Mars is on a wider orbit than Earth, therefore the baseline is longer. This creates more accurate distance measurements and the distances to the stars can now be greater. 5. The luminosity of the sun will not change because the luminosity is based on the radius of the object that the observer is on, everything else in the formula, including the Solar constant will stay the same number. 6. Yes two stars can have the same apparent magnitudes but different absolute magnitudes. A faint star can be closer to us while a bright star can be further away. Both can have the same apparent
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Unformatted text preview: magnitudes because both can look as bright. 7. Yes two stars can have the same absolute magnitudes but different apparent magnitudes. This can happen when the two stars are different distances from Earth, one being further than the other. 8. The star's apparent magnitude measures the brightness of a star as it appears to us here on Earth. A dim, close star will have a higher apparent magnitude then a bright, distant star. In reality, the bright, distant star has a higher energy output. So a star’s apparent magnitude is not a good indication of the star’s energy output. 9. Astronomers can estimate the chemical compositions of stars by looking at their spectrum. Each element has a different set of absorption lines in the spectrum. Each wavelength which can be measured and the absorption line at the given wavelength in a stellar spectrum shows that the element must be present....
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This note was uploaded on 10/25/2009 for the course PHYSICS Astronomy taught by Professor Me during the Spring '09 term at Akademia Ekonomiczna w Krakowie.

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