Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download No Slide Title
Document related concepts
Transcript
Binary Stars Double Stars/Binary Stars Earth Double Star Binary Star Earth Visual Binary Stars Orbit of Star 1 Center of Mass Orbit of Star 2 Sirius A & B Orbit of 12 Persei (Barlow, Scarfe, and Fekel Visual Binaries Stars must be either close to us or far from each other. Long orbital periods indicate they are far from each other. (years to decades) About 10% of all stars are visual binaries Possible planet detection Spectroscopic Binaries Spectrum of Hydrogen in Lab Spectrum a Star…..Day 1 Spectrum a Star…..Day 2 Spectrum a Star…..Day 3 Spectrum a Star…..Day 4 What do these spectra tell us about the star? Spectroscopic Binary Stars Radial Velocity Curve HDE 226868 Spectroscopic Binaries Orbital Stars Periods are several days are close together inclined 90° to sky are discovered this way. All of the extra-solar planets have been found in this way. Orbits Eclipsing Binary Stars Roche Lobes Classifications Detached 65 RT And Semi-detached 203 U Cep Over-Contact 12 XY Leo Star Light Pro Eclipsing Binaries Chances of finding an eclipsing binary 90° to sky Stars close together Inclined Same conditions as spectroscopic binary Many are discovered in both ways Eclipsing binaries also permit radius to be determined Relative radius Eclipse begins separation = sum of radii Second contact separation = difference in radii Time difference between these events gives radii of stars Mass-Luminosity Relationship
