The UBV(RI)_{C} Colors of the Sun
Abstract
Photometric data in the UBV(RI)_{C} system have been acquired for 80 solar analog stars for which we have previously derived highly precise atmospheric parameters T _{eff}, log g, and [Fe/H] using highresolution, high signaltonoise ratio spectra. UBV and (RI)_{C} data for 46 and 76 of these stars, respectively, are published for the first time. Combining our data with those from the literature, colors in the UBV(RI)_{C} system, with ~= 0.01 mag precision, are now available for 112 solar analogs. Multiple linear regression is used to derive the solar colors from these photometric data and the spectroscopically derived T _{eff}, log g, and [Fe/H] values. To minimize the impact of systematic errors in the modeldependent atmospheric parameters, we use only the data for the 10 stars that most closely resemble our Sun, i.e., the solar twins, and derive the following solar colors: (B  V)_{⊙} = 0.653 ± 0.005, (U  B)_{⊙} = 0.166 ± 0.022, (V  R)_{⊙} = 0.352 ± 0.007, and (V  I)_{⊙} = 0.702 ± 0.010. These colors are consistent, within the 1σ errors, with those derived using the entire sample of 112 solar analogs. We also derive the solar colors using the relation between spectrallinedepth ratios and observed stellar colors, i.e., with a completely modelindependent approach, and without restricting the analysis to solar twins. We find (B  V)_{⊙} = 0.653 ± 0.003, (U  B)_{⊙} = 0.158 ± 0.009, (V  R)_{⊙} = 0.356 ± 0.003, and (V  I)_{⊙} = 0.701 ± 0.003, in excellent agreement with the modeldependent analysis.
 Publication:

The Astrophysical Journal
 Pub Date:
 June 2012
 DOI:
 10.1088/0004637X/752/1/5
 arXiv:
 arXiv:1204.0828
 Bibcode:
 2012ApJ...752....5R
 Keywords:

 stars: fundamental parameters;
 Sun: fundamental parameters;
 techniques: photometric;
 Astrophysics  Solar and Stellar Astrophysics
 EPrint:
 ApJ, in press