AS101 Lecture Notes - Lecture 8: Main Sequence
Document Summary
A star system in which the stars are too close together to be visible separately. Light curve: a graph of brightness versus time commonly used in analyzing variable stars and eclipsing binaries. Density: average densities of main sequence stars are relatively low (similar to the sun"s density), giant stars have very low densities, white dwarfs have very high densities a single teaspoon of this material would have a mass of about 15 000 kg! Three important points: taking a survey is difficult because one must be sure to get an honest sample. If not enough stars are included in the survey, the results could be biased: m dwarfs and white dwarfs are so faint they are difficult to find even near earth and may be undercounted in surveys, luminous stars, although they are rare, are easily visible even at great distances.
