Characteristics of Spectral Classes Flashcards
What are the colour of O-class stars?
Blue
What are the colour of B-class stars?
Blue
What are the colour of A-class stars?
Blue-white
What are the colour of F-class stars?
White
What are the colour of G-class stars?
Yellow-white
What are the colour of K-class stars?
Orange
What are the colour of M-class stars?
Red
How does the colour vary over the different spectral classes?
O → F → M
Blue → White → Red
How does the temperature vary over the different spectral classes?
O → M
Hotter → Cooler
What is the temperature of O-class stars?
25,000K - 50,000K
What is the temperature of B-class stars?
11,000K - 25,000K
What is the temperature of A-class stars?
7,500K - 11,000K
What is the temperature of F-class stars?
6,000K - 7,500K
What is the temperature of G-class stars?
5,000K - 6,000K
What is the temperature of K-class stars?
3,500K - 5000K
What is the temperature of M-class stars?
< 3,500K
What are the strongest spectral line absorptions for O-class stars?
Helium ions and helium atoms
weak hydrogen
What are the strongest spectral line absorptions for B-class stars?
Helium atoms and Hydrogen
What are the strongest spectral line absorptions for A-class stars?
Strongest Hydrogen
some metal ion
What are the strongest spectral line absorptions for F-class stars?
Metal ions
What are the strongest spectral line absorptions for G-class stars?
Metal ions and metal atoms
What are the strongest spectral line absorptions for K-class stars?
Metal atoms
What are the strongest spectral line absorptions for M-class stars?
Cool enough for molecules to form;
Titanium oxide
How do the spectral lines vary over the different spectral classes?
Helium ions Helium atoms Hydrogen Metal ions Metal atoms Titanium oxide
