# IBVS 5482-t2.txt #IBVSdataKey: other Relation between Hp and V magnitudes The relation between the systems can be understood in terms of the color of the star. This table shows this relation as a function of B-V and spectral type of the star. The first column includes all of the stars up to A9 spectral type, and all the stars up to G0 -excepting those of the main sequence- and giants and subgiants between G1 and K9. Starting at class F, dwarfs (classes V and IV-V) show a slight difference that is reflected in the second column. For bright giants and supergiants (classes I and II) of spectral type G and K, the third column must be used. There's no way to establish a linear relation for stars of spectral type M or peculiar stars, since the presence of different molecules in the stellar atmosphere strongly influences the magnitude as measured by a filter with a broad band as the Hipparcos one. Note that when converting from B-V indexes as high as e.g. 1.9, we shouldn't include M stars but only stars strongly reddened by interstellar absorption. This proves that a linear conversion can be done using the B-V color index but as long as the star's atmosphere doesn't show chemical peculiarities that can "fool" the detector. Calibration is based in continuous comparison between Hp and V magnitudes performed by Otero while creating new photometric sequences and charts for bright variables. The main difference between this table and that presented by Bessell (2000) is the exclusion of all of the M stars from the relation. O3-A9I/V - F0-G0I/IV F0-K9V G1-K9I-II G1-K9III/IV B-V V-Hp -0.30 0.125 -0.29 0.120 -0.28 0.115 -0.27 0.108 -0.26 0.100 -0.25 0.094 -0.24 0.090 -0.23 0.087 -0.22 0.084 -0.21 0.079 -0.20 0.073 -0.19 0.067 -0.18 0.063 -0.17 0.059 -0.16 0.056 -0.15 0.051 -0.14 0.047 -0.13 0.043 -0.12 0.038 -0.11 0.033 -0.10 0.030 -0.09 0.026 -0.08 0.023 -0.07 0.019 -0.06 0.015 -0.05 0.010 -0.04 0.005 -0.03 0.002 -0.02 -0.001 -0.01 -0.005 0.00 -0.009 0.01 -0.012 0.02 -0.015 0.03 -0.018 0.04 -0.021 0.05 -0.024 0.06 -0.027 0.07 -0.031 0.08 -0.034 0.09 -0.037 0.10 -0.040 0.11 -0.043 0.12 -0.046 0.13 -0.048 0.14 -0.050 0.15 -0.052 0.16 -0.054 0.17 -0.057 0.18 -0.059 0.19 -0.061 0.20 -0.062 0.21 -0.064 0.22 -0.066 0.23 -0.067 0.24 -0.069 0.25 -0.070 0.26 -0.071 0.27 -0.072 0.28 -0.073 0.29 -0.074 0.30 -0.076 -0.075 0.31 -0.078 -0.076 0.32 -0.079 -0.077 0.33 -0.081 -0.078 0.34 -0.082 -0.079 0.35 -0.084 -0.080 0.36 -0.086 -0.081 0.37 -0.087 -0.082 0.38 -0.089 -0.083 0.39 -0.091 -0.084 0.40 -0.092 -0.086 0.41 -0.093 -0.088 0.42 -0.095 -0.090 0.43 -0.096 -0.092 0.44 -0.098 -0.094 0.45 -0.100 -0.096 0.46 -0.102 -0.097 0.47 -0.103 -0.098 0.48 -0.105 -0.100 0.49 -0.107 -0.103 0.50 -0.109 -0.105 0.51 -0.111 -0.107 0.52 -0.113 -0.109 0.53 -0.115 -0.110 0.54 -0.117 -0.112 0.55 -0.120 -0.114 0.56 -0.122 -0.116 0.57 -0.124 -0.117 0.58 -0.125 -0.118 0.59 -0.126 -0.120 0.60 -0.127 -0.122 0.61 -0.128 -0.123 0.62 -0.129 -0.124 0.63 -0.130 -0.125 0.64 -0.131 -0.126 0.65 -0.132 -0.128 0.66 -0.133 -0.129 0.67 -0.134 -0.130 0.68 -0.136 -0.131 0.69 -0.137 -0.132 0.70 -0.138 -0.134 0.71 -0.139 -0.135 0.72 -0.140 -0.136 0.73 -0.141 -0.137 0.74 -0.142 -0.138 0.75 -0.143 -0.139 0.76 -0.144 -0.140 0.77 -0.145 -0.141 0.78 -0.147 -0.142 0.79 -0.148 -0.142 0.80 -0.149 -0.143 0.81 -0.150 -0.143 0.82 -0.151 -0.144 0.83 -0.152 -0.144 0.84 -0.153 -0.145 0.85 -0.154 -0.145 0.86 -0.155 -0.146 0.87 -0.156 -0.147 0.88 -0.156 -0.147 0.89 -0.157 -0.148 0.90 -0.157 -0.149 0.91 -0.158 -0.149 0.92 -0.159 -0.150 0.93 -0.159 -0.151 0.94 -0.160 -0.151 0.95 -0.160 -0.152 0.96 -0.161 -0.153 0.97 -0.161 -0.153 0.98 -0.162 -0.154 0.99 -0.163 -0.154 1.00 -0.163 -0.155 1.01 -0.164 -0.155 1.02 -0.165 -0.156 1.03 -0.165 -0.156 1.04 -0.166 -0.157 1.05 -0.166 -0.157 -0.167 1.06 -0.167 -0.158 -0.168 1.07 -0.168 -0.158 -0.169 1.08 -0.168 -0.158 -0.170 1.09 -0.169 -0.158 -0.171 1.10 -0.169 -0.159 -0.172 1.11 -0.169 -0.159 -0.174 1.12 -0.170 -0.159 -0.175 1.13 -0.170 -0.160 -0.177 1.14 -0.171 -0.160 -0.179 1.15 -0.171 -0.160 -0.180 1.16 -0.171 -0.160 -0.180 1.17 -0.170 -0.160 -0.180 1.18 -0.170 -0.159 -0.179 1.19 -0.170 -0.159 -0.179 1.20 -0.169 -0.159 -0.178 1.21 -0.169 -0.159 -0.178 1.22 -0.168 -0.158 -0.176 1.23 -0.168 -0.158 -0.175 1.24 -0.167 -0.158 -0.173 1.25 -0.166 -0.157 -0.172 1.26 -0.165 -0.157 -0.171 1.27 -0.164 -0.156 -0.170 1.28 -0.162 -0.156 -0.169 1.29 -0.160 -0.155 -0.168 1.30 -0.159 -0.155 -0.167 1.31 -0.157 -0.154 -0.166 1.32 -0.155 -0.153 -0.165 1.33 -0.153 -0.151 -0.164 1.34 -0.151 -0.163 1.35 -0.149 -0.163 1.36 -0.148 -0.162 1.37 -0.147 -0.162 1.38 -0.146 -0.161 1.39 -0.145 -0.161 1.40 -0.144 -0.160 1.41 -0.143 -0.159 1.42 -0.142 -0.159 1.43 -0.141 -0.158 1.44 -0.140 -0.157 1.45 -0.138 -0.156 1.46 -0.135 -0.155 1.47 -0.133 -0.154 1.48 -0.131 -0.153 1.49 -0.129 -0.152 1.50 -0.127 -0.151 1.51 -0.125 -0.150 1.52 -0.123 -0.149 1.53 -0.121 -0.148 1.54 -0.120 -0.147 1.55 -0.119 -0.145 1.56 -0.118 -0.144 1.57 -0.117 -0.143 1.58 -0.116 -0.141 1.59 -0.115 -0.140 1.60 -0.114 -0.139 1.61 -0.113 -0.138 1.62 -0.112 -0.137 1.63 -0.111 -0.136 1.64 -0.110 -0.135 1.65 -0.109 -0.134 1.66 -0.108 -0.133 1.67 -0.107 -0.132 1.68 -0.106 -0.131 1.69 -0.105 -0.130 1.70 -0.104 -0.129 1.71 -0.103 1.72 -0.102 1.73 -0.101 1.74 -0.100 1.75 -0.099 1.76 -0.098 1.77 -0.098 1.78 -0.097 1.79 -0.097 1.80 -0.096 1.81 -0.095 1.82 -0.094 1.83 -0.093 1.84 -0.092 1.85 -0.091 1.86 -0.090 1.87 -0.089 1.88 -0.088 1.89 -0.087 1.90 -0.086 1.91 -0.086 1.92 -0.085 1.93 -0.084 1.94 -0.083 1.95 -0.082 1.96 -0.081 1.97 -0.080 1.98 -0.079 1.99 -0.078 2.00 -0.077 * Bessell, M., 2000, PASP, 112, 961-965, The Hipparcos and Tycho Photometric System Passbands. * Perryman, M.A.C., et al., 1997, The Hipparcos and Tycho Catalogues, ESA SP-1200 Otero, 2001.