Spectral Types

The spectral type is used to look up the AB_nu value in a table (see below or WFPC2 Instrument Handbook Vers. 3.0, Table 6.1, p. 67).

AB_nu values as a function of Wavelength and Spectral Type:

                                         Spectral Type 
           -------------------------------------------------------------------------
           Sky    B0     A0    F0    G0   K0III  M0III   gE    Sa    Sbc   Scd   IrI
   (B-V):  1.10  -0.30  0.00  0.27  0.58  1.07   1.60   1.00  0.80  0.60  0.45  0.30
           ----  -----  ----  ----  ----  -----  -----  ----  ----  ----  ----  ----
Wavelength
   (A) 
----------
 1500      2.45  -1.60  2.22  7.22  8.9    13     15    6.82  5.40  4.03  2.67  1.77
 2000      5.46  -1.50  1.35  4.10  6.35  10.3   12.3   6.41  4.80  3.18  2.29  1.40
 2500      5.46  -1.20  1.11  3.11  4.61  8.11   9.36   5.43  4.10  2.86  2.15  1.36
 3000      3.12  -0.78  1.21  1.99  2.46  5.46   6.21   3.63  3.00  2.46  1.76  1.24
 3500      2.00  -0.62  1.00  1.38  1.63  2.13   4.63   2.49  2.01  1.54  1.35  0.94
 4000      1.03  -0.46 -0.23  0.29  0.67  1.16   2.26   1.40  1.12  0.84  0.65  0.43
 4500      0.55  -0.36 -0.16  0.06  0.26  0.46   0.96   0.55  0.44  0.34  0.28  0.34
 5000      0.18  -0.22 -0.09  0.03  0.08  0.2    0.51   0.21  0.19  0.17  0.13  0.17
 6000     -0.11   0.16  0.11  0.03 -0.04 -0.24  -0.46  -0.19 -0.17 -0.14 -0.11  0.13
 7000     -0.33   0.46  0.22  0.05 -0.12 -0.42  -0.76  -0.52 -0.44 -0.37 -0.26 -0.04
 8000     -0.55   0.76  0.33  0.08 -0.21 -0.61  -1.06  -0.81 -0.7  -0.6  -0.39 -0.21
 9000     -0.65   0.96  0.36  0.09 -0.23 -0.66  -1.12  -1.07 -0.95 -0.84 -0.47 -0.33
10000     -0.75   1.17  0.4   0.1  -0.25 -0.72  -1.19  -1.29 -1.16 -1.04 -0.58 -0.45