Unformatted text preview: Less than 1% of stars in solar neighborhood are giants and super giants 1913 Henry Norris Russell (American Astronomer) had parallax distances to these stars in the solar neighborhood and plotted them on this diagram. o Could determine their luminosities from inverse sqare law and apparent brightness o He missed stars of high L because there are too few nearby o Still saw M-S pattern o 1911: E. Hertsprung, Danish astronomer studied stars in star clusters plotting brightness vs. color index. Star cluster all stars roughly same distance from earth implies all F, for stars yield L’s by same inverse square law Color index was consistent with surface temperature and spectral type o...
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- Spring '07
- main sequence, white dwarfs, solar neighborhood, Henry Norris Russell