AST-1002 Chapter 11: AST Chapter 11
Document Summary
The brightnesses of stars measured without regard to their distances from earth are called apparent magnitudes, denoted by lowercase m. The brightest stars were originally said to be of first magnitude, and their apparent magnitudes were designated m = +1. Greek astronomers did not try to classify the sun"s dazzling brightness in this scheme. Because stars do not appear with discrete levels of brightness, this system has non integer magnitudes as well, such as +3. 5 or +4. 8. Numbering as well as naming schemes may be counterintuitive in science. You might expect brighter stars to have larger, more positive numbers than dimmer stars, but the apparent magnitude scheme is just the opposite. Similarly, we will see shortly that on the standard plot of stars used by astronomers, the. Hertzsprung-russell diagram, the hottest stars fall on the left and the coolest stars on the right. Absolute magnitude, m, is the brightness each star would have at a distance of 10 pc.
