ASTR 1102 Study Guide - Rr Lyrae Variable, Galactic Center, Interstellar Medium
Document Summary
23-1 the sun is located in the disk of our galaxy, about 8000 parsecs from the galactic center: a galaxy is an immense collection of stars and interstellar matter, far larger than a star cluster. Locating the sun within the galaxy: early attempts: we have an edge-on view from inside the pancake-like disk of our own milky. Way galaxy, which is why the milky way appears as a band around the sky: until the twentieth century, the prevailing opinion was that the sun and planets lie at the galaxy"s center. One of the first to come to this conclusion was the eighteenth-century english astronomer william herschel. Who discovered the planter uranus and was a pioneering cataloger of binary star systems: herschel found approximately the same density of stars all along the milky. Therefore, he concluded that we are at the center of our galaxy: according the kapteyn, the milky way is about 17 kpc (17 kiloparsecs =
