Lecture 16
Variable stars
Tuesday July 29, 2008
Slides on Angel
Concepts:
- Algol: Eclipsing binary system in which the more massive star is less evolved; companion was initially more massive, evolved into subgiant phase, transferred lots of mass
- Beta Lyrae: Close stars deformed by gravity into ellipsoids; the one gaining mass is probably surrounded by torus of infalling material
- UV Ceti: Red dwarf that shows short bursts; like solar flares, thought to be caused by magnetic recombination events
- Mira: Red giant with slow period (~330d), winds driving off matter that trails behind moving star
- Delta Cephei: Cepheids have predictable luminosities; larger for longer pulsation periods, luminous enough to use to measure distance to nearby galaxies
- R Cor Bor: Condensation of ejected carbon into soot blocks out visible light from star until clouds disperse or destroyed (light curve like "reverse nova")
Activity:
Guessed answers to series of questions presented during lecture.
Random link:
None