EPSC 180 Lecture Notes - Lecture 1: G-Type Main-Sequence Star, Main Sequence, Red Dwarf
10 Apr 2018
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Document Summary
Vega: bright white star(we dunnno if naturally bright or just close to us) absolute magnitude(how bright is a star) Whenever double distance, star is a quarter away. As earth orbit in sun, perception to sun different (look like moving in background. We measure against the background of fixed stars. What is distance from earth to sun= i au (astronomers unit) As star is farther and farther away, the angle would reduce(so distance is inversely to the angle) Closest star called proxima centauri ~ 1. 29 parsec(pc) Angles get too small to meaure when 360 parsec distance (1000 light years distance) hhipparcos satellites (who invented magnitude scale), we can determine the distance to stars w/ distances of 300 pc w/ accuracy of 10% Sun= g2v star (w/ surface t 5800 k) Should know that is is a yellow dwarf (g2) hydrogen helium stage. Spectral type: color they are, how hot surface is.
