AS102 Study Guide - Midterm Guide: Main Sequence, Milky Way, Cosmic Distance Ladder
Document Summary
Here, things are getting a little more complicated. Comparing stars similar to our sun throughout our galaxy gets difficult because g2 stars are actually not all that bright (they certainly wouldn"t get a. Laurier degree!) and such stars cannot be useful at distances much beyond 1,000 ly. Therefore, we must find brighter standard candles and bigger, brighter main sequence stars seem to be ideal candidates. This method is known as main sequence fitting and is based on our knowledge of stars in the hyades cluster in taurus. This technique is also used for measuring distances to single stars, although the uncertainty in such measurements is often greater than for stars in clusters. This technique is used extensively for measuring distances within our own milky way galaxy. So, main sequence fitting works well within our own galaxy but not for stars in clusters in other galaxies, which are too dim for this technique.
