Spectral Type and Tsurface in degrees Kelvin (Zombeck)
   Regular Main Sequence Stars [V]    || Giant Stars [III]
Type  Temp    Type Temp   Type  Temp  || Type  Temp
O5-O7 38000K  A0  10800K  K0    5240K || G5    5010K
O8-O9 35000K  A2   9730K  K2    4780K || G8    4870K
O9.5  31900K  A5   8620K  K5    4558K?|| K0    4720K
              A7   8190K  K7    4410K || K2    4460K
B0    30000K                          || K3    4210K
B0.5  27000K  F0   7240K  M0    3920K || K4    4010K
B1    24200K  F2   6930K  M1    3680K || K5    3780K
B2    22100K  F5   6540K  M2    3500K || M0    3660K
B3    18800K  F8   6200K  M3    3360K || M1    3600K
B5    16400K              M4    3230K || M2    3500K
B6    15400K  G0   5920K  M5    3120K || M3    3300K
B7    14500K  G2   5780K  M6    2500K?|| M4    3100K
B8    13400K  G5   5610K  M7    2380K?|| M5    2950K
B9    13400K  G8   5490K  M8    2260K || M6    2800K
Spectral Type Characteristics
O > 25000K,          B 11000K < T < 25000K, A 7500K < T < 11000K
F 6000K < T < 7500K, G 5000K < T < 6000K,   K 3500K < T < 5000K
M 2200K < T < 3500K. Classes with different spectral lines are:
S 2200K < T < 3500K, R(C) 3500K < T < 5000K,N(C) 2200 < T < 3500,
W > 25000K,          WC > 25000K,           WN > 25000K [Wolf-Rayets]
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