ASTRON 2B03 Lecture Notes - Lecture 10: Bell Labs, Hertzsprung (Crater), Hipparcos
10 Apr 2018
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Document Summary
Mass (but only if in binary system) stars. Need to build models of our universe. Ages of oldest stars = constraints for universe timelines. Distance under certain circumstances (can"t nd accurately always) parallax. Mass only if the star is in a binary system, can predict anything if you know mass and age we can measure brightness and how hot their surface temp is easily. Hertzsprung russell colour-magnitude diagram o top of luminosity axis (bright: bottom of luminosity axis (faint) o main sequence = stars burning hydrogen (long diagonal line) Main sequence = long diagonal line co2lour-magnitude diagrams of. Diagrams of stars within 5 parsecs of the sun. 100 brightest stars in the sky are relatively distant from us, tend to be massive and still burning hydrogen, and giants/supergiants. Measure nearby stars (out to 200 pc), launched 1989. Measure accurate distance to cepheid variable star. Pulsing variable stars where true brightness is known.
