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AS2020: Astronom ía Contemporánea Clase # 13 Cosmología. Profesor: Jos é Maza Sancho 10 Noviembre 2010. Distances of Galaxies. Radar ranging: Astronomical unit Stellar parallax Standard candles: Main-sequence fitting. Cepheid Variables.
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AS2020: Astronomía ContemporáneaClase # 13Cosmología • Profesor: José Maza Sancho • 10 Noviembre 2010
Distances of Galaxies • Radar ranging: Astronomical unit • Stellar parallax • Standard candles: • Main-sequence fitting
Cepheid Variables • In 1912 Miss Henrietta Leavitt discovered the period-luminosity relation.
Type Ia Supernovae • MB(max) ~ -19.5 (L ~ 5x109 Lo) • MB(max) versus rate of decline
Distance Chain Summary • Radar ranging • Parallax • Main-sequence fitting • Cepheid variables • Type Ia supernovae • Hubble’s law
How do distance measurements tell us the age of the universe. • Age 12 ~ 15 billion years • Age (CMB) ~ 13.7 billion years