ASTR 121 Study Guide - Midterm Guide: Cno Cycle, Planetary Nebula, Triple-Alpha Process
9 Aug 2016
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Document Summary
Spectroscopic- the orbit can be determined by measuring doppler shifts. The brightness of a star depends on its distance and luminosity. The lower the apparent magnitude is, the brighter it appears when you observe it from earth. The faintest stars have an apparent magnitude of 6. 0. The graph plots luminosities and temperatures of stars. (temperature decreases from left to right and luminosities increase from bottom to top). Most stars lie on the main sequence of the diagram, but white dwarfs appear on the lower left side and red giants and supergiants appear on the upper right side. Stars" stellar properties depend on mass and age, and will stay on the main sequence as long as they can still fuse hydrogen into helium in their cores. Red giants/supergiants have already used up their core hydrogen, and white dwarfs appear after fusion has ceased. Interstellar medium- the gas and dust between the stars.
