Star color
- blackbody approximation

Mitchell Charity <mcharity@lcs.mit.edu>
  > What color are the stars?
  >   > Star color - details
  >   > Star color - data comparison
  >   >   > Star color - data plots
  >   > Star color - blackbody approximation
  >   > What color is the Sun?
  > What color is a blackbody?

Here are colors for various black body radiation Teff's.

Main sequence stars
Sp(V)U-VB-VV-ITe(K)color
  O   O5-7-1.46-0.32-0.4738000  #a2b8ff
O8-9-1.44-0.31-0.4735000  #a3b8ff
O9.5-1.40-0.30-0.4631900  #a4baff
  B   B0-1.38-0.30-0.4230000  #a5baff
B0.5-1.29-0.28-0.3927000  #a7bcff
B1-1.19-0.26-0.3624200  #a9bdff
B2-1.10-0.24-0.3222100  #abbfff
B3-0.91-0.20-0.2718800  #afc2ff
B5-0.72-0.16-0.2216400  #b4c6ff
B6-0.63-0.14-0.1915400  #b6c8ff
B7-0.54-0.12-0.1714500  #b9caff
B8-0.39-0.09-0.1213400  #bccdff
B9-0.25-0.06-0.0612400  #c1d0ff
  A   A0+0.00+0.00+0.0010800  #cad6ff
A3+0.12+0.06+0.099730  #d2dcff
A5+0.25+0.14+0.228620  #dde4ff
A7+0.30+0.19+0.288190  #e3e8ff
  F   F0+0.37+0.31+0.477240  #f2f2ff
F2+0.39+0.36+0.556930  #f9f6ff
F5+0.43+0.43+0.646540  #fff9fc
F8+0.60+0.54+0.766200  #fff6f3
  G   G0+0.70+0.59+0.815920  #fff3eb
G2+0.79+0.63+0.865780  #fff1e7
G5+0.86+0.66+0.895610  #ffefe1
G8+1.06+0.74+0.965490  #ffeedd
  K   K0+1.29+0.82+1.065240  #ffead5
K2+1.60+0.92+1.224780  #ffe4c4
K5+2.18+1.15+1.62-  #ffdfb8
K7+2.52+1.30+1.934410  #ffddb4
  M   M0+2.67+1.41+2.193920  #ffd39d
M1+2.70+1.48+2.453680  #ffcd91
M2+2.69+1.52+2.693500  #ffc987
M3+2.70+1.55+2.943360  #ffc57f
M4+2.70+1.56+3.193230  #ffc177
M5+2.80+1.61+3.473120  #ffbd71
M6+2.99+1.72+3.76-  #ffb866
M7+3.24+1.84+4.20-  #ffb25b
M8(+3.50)(+2.00)(+4.70)2660  #ffad51
Giant stars
Sp(III)U-VB-VV-ITe(K)color
  G   G5+1.55+0.92+1.175010  #ffe7cc
G8+1.64+0.95+1.184870  #ffe5c7
  K   K0+1.93+1.04+1.304720  #ffe3c1
K1+2.13+1.10+1.374580  #ffe0bc
K2+2.32+1.16+1.424460  #ffdeb6
K3+2.74+1.30+1.614210  #ffd9ab
K4+3.07+1.41+1.814010  #ffd5a2
K5+3.34+1.54+2.103780  #ffd096
  M   M0+3.43+1.55+2.173660  #ffcd90
M1+3.48+1.56+2.273600  #ffcb8d
M2+3.51+1.59+2.443500  #ffc987
M3+3.51+1.60+2.793300  #ffc37c
M4+3.32+1.59+3.393100  #ffbd6f
M5+3.00+1.55+4.142950  #ffb866
M6+2.43+1.54+5.062800  #ffb25b
Table copied (column-wise abbreviated) from
Handbook of Space Astronomy and Astrophysics
pages 68 , 69 , 70
Values were handcopied with minimal checking.
SpTe(K)color
 O6-O8V38000 #a2b8ff  162,184,388
 O9V33200 #a3b9ff  163,185,389
 O9.5V31450 #a4baff  164,186,390
 B0V29700 #a5baff  165,186,390
 B1V25600 #a8bdff  168,189,393
 B2V22300 #abbfff  171,191,401
 B3V19000 #afc2ff  175,194,404
 B4V17200 #b2c5ff  178,197,407
 B5V15400 #b6c8ff  182,200,512
 B6V14100 #bacbff  186,203,515
 B7V13000 #beceff  190,206,518
 B8V11800 #c4d2ff  196,210,528
 B8V10700 #cad7ff  202,215,533
 A0V9480 #d4deff  212,222,546
 A2V8810 #dbe2ff  219,226,550
 A5V8160 #e3e8ff  227,232,562
 A7V7930 #e7eaff  231,234,564
 F0V7020 #f7f5ff  247,245,581
 F2V6750 #fdf9ff  253,249,585
 F5V6530 #fff9fb  255,249,585
 F7V6240 #fff6f4  255,246,582
 G0V5930 #fff3eb  255,243,579
 G2V5830 #fff2e8  255,242,578
 G4V5740 #fff1e5  255,241,577
 G6V5620 #ffefe2  255,239,569
 K0V5240 #ffead5  255,234,564
 K2V5010 #ffe7cc  255,231,561
 K4V4560 #ffe0bb  255,224,548
 K5V4340 #ffdcb1  255,220,544
 K7V4040 #ffd6a3  255,214,532
 M0V3800 #ffd097  255,208,520
 M1V3680 #ffcd91  255,205,517
 M2V3530 #ffc989  255,201,513
 M3V3380 #ffc580  255,197,407
 M4V3180 #ffbf74  255,191,401
 M5V3030 #ffba6b  255,186,390
 M6V2850 #ffb45f  255,180,384
 G0III5910 #fff3ea  255,243,579
 G4III5190 #ffead3  255,234,564
 G6III5050 #ffe8ce  255,232,562
 G8III4960 #ffe6cb  255,230,560
 K0III4810 #ffe4c5  255,228,552
 K1III4610 #ffe1bd  255,225,549
 K2III4500 #ffdfb8  255,223,547
 K3III4320 #ffdbb0  255,219,537
 K4III4080 #ffd6a5  255,214,532
 K5III3980 #ffd4a0  255,212,530
 M0III3820 #ffd198  255,209,521
 M1III3780 #ffd096  255,208,520
 M2III3710 #ffce93  255,206,518
 M3III3630 #ffcc8e  255,204,516
 M4III3560 #ffca8b  255,202,514
 M5III3420 #ffc683  255,198,408
 M6III3250 #ffc179  255,193,403
 O9I32500 #a4b9ff  164,185,389
 B0I26000 #a7bcff  167,188,392
 B1I20700 #acc0ff  172,192,402
 B2I17800 #b1c4ff  177,196,406
 B3I15600 #b6c8ff  182,200,512
 B4I13900 #bbcbff  187,203,515
 B5I13400 #bccdff  188,205,517
 B6I12700 #bfcfff  191,207,519
 B7I12000 #c3d1ff  195,209,521
 B8I11200 #c7d4ff  199,212,530
 B9I10500 #ccd8ff  204,216,534
 A0I9730 #d2dcff  210,220,544
 A1I9230 #d6dfff  214,223,547
 A2I9080 #d8e0ff  216,224,548
 A5I8510 #dfe5ff  223,229,553
 F0I7700 #eaedff  234,237,567
 F2I7170 #f4f3ff  244,243,579
 F5I6640 #fffafe  255,250,592
 F8I6100 #fff5f0  255,245,581
 G0I5510 #ffeede  255,238,568
 G3I4980 #ffe7cb  255,231,561
 G8I4590 #ffe0bc  255,224,548
 K0I4420 #ffddb5  255,221,545
 K1I4330 #ffdcb1  255,220,544
 K2I4260 #ffdaae  255,218,536
 K3Iab4130 #ffd8a8  255,216,534
 K5Iab3850 #ffd19a  255,209,521
 M0Iab3650 #ffcc8f  255,204,516
 M1Iab3550 #ffca8a  255,202,514
 M2Iab3450 #ffc784  255,199,409
 M3Iab3200 #ffc076  255,192,402
 M4Iab2980 #ffb968  255,185,389
Effective Temperatures And Intrinsic Colors
For Main Sequence (V), Giant (III), And Supergiant (I) Stars
- Tokunaga

Sun
as G2(V) Handbook 5780 #fff1e7
as G2(V) Tokunaga 5830 #fff2e8
5770 K blackbody appoximation #fff1e6
from spectrum (ref) #fff3ea

Notes

These blackbody pixel colors are not unique.
My choices of color system, white point, and gamma, while plausible, do nontrivially affect the selection of pixel values. Mainly whitepoint. See What color is a blackbody? for further discussion. Also, color calibration varies between monitors.

Blackbody color calculation
These colors were calculated using the CIE 1931 2 degree Color Matching Functions as modified by Judd (1951) and Vos (1978) , and the sRGB's color space primaries and gamma correction, and a D65 whitepoint.

Which numbers?
There is variety in the Teff numbers quoted on the web. I got these from the plausible sources indicated.

Do these blackbody colors seem completely wrong?
Perhaps it is a whitepoint issue. See What color is a blackbody?.

Links

What color is a blackbody?

Comments encouraged - Mitchell Charity <mcharity@lcs.mit.edu> 

Notes:

Doables:
  Break up Tokunaga, aligning types.
  Turn Tokunaga colour indexes back on?
  Integrate tables.
  Add decimal (0-255) values everywhere.
  The black background was nice(r)?... (and less browser variable)  Force gray?
  "color" and 'colour" oh my.

History:
  2002-Nov-11  Fixed links broken by CVRL move.
  2001-Jun-04 on-line