3rd EditionAbe Mizrahi, Edward E. Prather, Gina Brissenden, Jeff P. Adams429 explanations
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14th EditionDana E. Backman, Michael A. Seeds498 explanations
1st EditionEric Mazur2,411 explanations
ASTRONOMYTable lists the temperature ranges that correspond to the different spectral types. What part of the star do these temperatures refer to? Why?
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\begin{matrix}
\text{Spectral Classes for Stars}\\
\text{Spectral Class} & \text{Color} & \text{Aproximate Temperature (K)} & \text{Principal Features} & \text{Examples}\\
\text{O} & \text{Blue} & \text{>30,000} & \text{Neutral and ionized helium lines, weak hydrogen lines} & \text{10 Lecertae}\\
\text{B} & \text{Blue-white} & \text{10,000-30,000} & \text{Neutral helium lines, strong hydrogen lines} & \text{Rigel, Spica}\\
\text{A} & \text{White} & \text{7500-10,000} & \text{Strongest hydrogen lines, weak ionized calcium lines, weak ionized metal (e.g., iron, magnesium ) lines} & \text{Sirius, Vega}\\
\text{F} & \text{Yellow-white} & \text{6000-7500} & \text{Strong hydrogen lines, strong ionized calcium lines, weak sodium lines, many ionized metal lines} & \text{Canopus, Procyon}\\
\text{G} & \text{Yellow} & \text{5200-6000} & \text{Weaker hydrogen lines, strong ionized calcium lines, strong sodium lines, many lines of ionized and neutral metals.} & \text{Sun, Capella}\\
\text{K} & \text{Orange} & \text{3700-5200} & \text{Very weak hydrogen lines, strong ionized calcium lines, strong sodium lines, many lines of neutral metals} & \text{Arcturus, Aldebaran}\\
\text{M} & \text{Red} & \text{2400-3700} & \text{Strong lines of neutral metals and molecular bands of titanium oxide dominate} & \text{Betelgeuse, Antares}\\
\text{L} & \text{Red} & \text{1300-2400} & \text{Metal hydride lines, alkali metal lines (e.g., sodium, potassium, rubidium)} & \text{Teide 1}\\
\text{T} & \text{Magenta} & \text{700-1300} & \text{Methane lines} & \text{Gliese 229B}\\
\text{Y} & \text{Infrared} & \text{<700} & \text{Ammonia lines} & \text{WISE 1828+2650}\\
\end{matrix}
$$
