(V-R,R-I,V-I,Fe) or (Y-V,V-S,Fe) or (B1-B2,B2-G,B2-V1,Fe)  ->  Teff
Melendez and Ramirez, 2003, A&A 398, 705
IRFM temperature calibrations for the Vilnius, Geneva, RIc and DDO photometric systems.

theta = 5040/Teff

Vilnius:

theta = +0.248 + 1.336*(V-S) - 0.354*[(V-S)^2] - 0.029*[Fe/H] - 0.008*([Fe/H]^2)

0.40 < (V-S) < 1.20 for -0.5 < [Fe/H] < +0.5
0.40 < (V-S) < 0.70 for -1.5 < [Fe/H] < -0.5
0.45 < (V-S) < 0.70 for -2.5 < [Fe/H] < -1.5

standard deviation in Teff: 104K

theta = +0.330 + 0.981*(Y-V) - 0.033*[Fe/H] - 0.009*([Fe/H]^2)

0.40 < (Y-V) < 1.05 for -0.5 < [Fe/H] < +0.5
0.40 < (Y-V) < 0.65 for -1.5 < [Fe/H] < -0.5
0.45 < (Y-V) < 0.70 for -2.5 < [Fe/H] < -1.5

standard deviation in Teff: 126K

Geneva:

theta = +0.629 + 0.644*(B2-V1) + 0.065*[(B2-V1)^2] - 0.033*(B2-V1)*[Fe/H] - 
- 0.029*[Fe/H] - 0.010*([Fe/H]^2)

0.10 < (B2-V1) < 1.05 for -0.5 < [Fe/H] < +0.5
0.10 < (B2-V1) < 0.60 for -1.5 < [Fe/H] < -0.5
0.20 < (B2-V1) < 0.60 for -2.5 < [Fe/H] < -1.5
0.20 < (B2-V1) < 0.50 for -3.5 < [Fe/H] < -2.5

standard deviation in Teff: 90K

theta = +0.838 + 0.501*(B2-G) - 0.030*[(B2-G)^2] - 0.044*[Fe/H] - 0.010*([Fe/H]^2)

-0.30 < (B2-G) < 1.10 for -0.5 < [Fe/H] < +0.5
-0.25 < (B2-G) < 0.40 for -1.5 < [Fe/H] < -0.5
-0.20 < (B2-G) < 0.40 for -2.5 < [Fe/H] < -1.5
-0.20 < (B2-G) < 0.30 for -3.5 < [Fe/H] < -2.5

standard deviation in Teff: 86K

t = (B2-G) - 0.39*(B1-B2)

theta = +0.768 + 0.578*t + 0.426*(t^2) - 0.020*[Fe/H] - 0.007*([Fe/H]^2)

-0.10 < t < 0.45 for -0.5 < [Fe/H] < +0.5
-0.05 < t < 0.40 for -1.5 < [Fe/H] < -0.5
+0.00 < t < 0.45 for -2.5 < [Fe/H] < -1.5
+0.00 < t < 0.30 for -3.5 < [Fe/H] < -2.5

standard deviation in Teff: 75K

Johnson:

theta = +0.516 + 1.085*(V-R)c - 0.203*[(V-R)c^2] - 0.120*(V-R)c*[Fe/H] + 0.025*[Fe/H]

0.20 < (V-R)c < 0.90 for -0.5 < [Fe/H] < +0.5
0.20 < (V-R)c < 0.50 for -1.5 < [Fe/H] < -0.5
0.25 < (V-R)c < 0.45 for -2.5 < [Fe/H] < -1.5

standard deviation in Teff: 91K

theta = +0.422 + 1.557*(R-I)c - 0.563*[(R-I)c^2] - 0.140*(R-I)c*[Fe/H] + 0.055*[Fe/H]

0.20 < (R-I)c < 0.80 for -0.5 < [Fe/H] < +0.5
0.30 < (R-I)c < 0.45 for -1.5 < [Fe/H] < -0.5
0.30 < (R-I)c < 0.50 for -2.5 < [Fe/H] < -1.5

standard deviation in Teff: 80K

theta = +0.483 + 0.617*(V-I)c - 0.072*[(V-I)c^2] - 0.066*(V-I)c*[Fe/H] + 
+0.023*[Fe/H] - 0.008*([Fe/H]^2)

0.40 < (V-I)c < 1.70 for -0.5 < [Fe/H] < +0.5
0.40 < (V-I)c < 1.00 for -1.5 < [Fe/H] < -0.5
0.55 < (V-I)c < 0.90 for -2.5 < [Fe/H] < -1.5

standard deviation in Teff: 64K