"It plots two basic properties of stars: their luminosity (intrinsic brightness) and their surface temperature (as revealed by their color). In doing so, it anchors stellar astronomy just as the periodic table anchors chemistry. Whereas the periodic table groups together similar chemical elements -- for example, placing all noble gases, such as helium, neon and argon, into one column -- the H-R diagram groups together stars passing through similar stages of life."
06 July 2011
Star Chart ~ SciAm Shares Stellar H-R Diagram!
The latest Scientific American comes with gratis star chart -- a Hertzsprung-Russell (H-R) Diagram -- a kind of stellar periodic table!