2007-01-07 06:15:32 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
The Hertzsprung-Russel (HR) diagram plots luminosity (magnitude) versus spectral class, color index, or temperature. The sequence of spectral class (O,B,A,F,G,K,M,L, with numerical subdivisions) follows decreasing surface temperature or color from blue to red. Color-magnitude diagrams are often used, for studying star clusters, for example, because the color index of a star is more easily determined than its spectral class. For theoretical purposes, astrophysicists often plot temperature-luminosity diagrams.
These three types of diagrams are subtly different, but all are often referred to as HR diagrams. The original HR diagram used spectral class.
2007-01-07 07:34:17 · answer #1 · answered by injanier 7 · 0⤊ 0⤋
The vertical position represents the star's luminosity. The horizontal position represents the star's surface temperature.
2007-01-07 14:22:27 · answer #2 · answered by gebobs 6 · 1⤊ 0⤋
Luminosity and effective temperature. The luminosity is usually on a logarithmic scale.
2007-01-07 14:22:14 · answer #3 · answered by elohimself 4 · 1⤊ 0⤋