AST 10G Lecture Notes - Lecture 9: Blue Light, Red Light, Henrietta Swan Leavitt, Inverse-Square Law
Document Summary
Chapter 19: our s. s, stars (ms, giants, wd, star clusters (open & globular, neutron stars, pulsars black holes. Stars are distributed non-randomly in sky: clusters, constellations appear to be related groups, there is the band of light across sky-milky way, dust lanes. The milk way: galileo showed mw-countless stars, clusters, glowing nebulae, & dark dust lanes, harlow shapley-measured glob. Cluster figure out how far away they are then can figure out size : rr lyrae variable stars to measure distance of globular clusters. Cepheid variable stars: most pulsating variable stars inhabit instability strip on the h-r diagram, most luminous ones are cepheid variables, ceph9red giants going through instability strip. Milky way: sun quite distant from center of globular cluster system. Galactic spiral arms: measurement of the position and motion of gas clouds shows that the milky way has spiral form ( loose , most stars are on spiral arms .
