Luminosity Classes
�
Ia
��
Bright supergiant
�
Ib
��
Supergiant
�
II
��
Bright giant
�
III
��
Giant
�
IV
��
Subgiant
�
V
��
Main sequence star
�
white dwarfs not given
Roman numeral
�
Sun:
��
G2 V
�
Rigel:
�
B8 Ia
�
Betelgeuse:
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M2 Iab