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On Tue, 27 May 2003, Sebastian Otero wrote: > About the use of the red star, (V=11.1) RS oph is not blue (the red giant in > the system is the dominant light now) but it has a B-V around 0.9-1.2 so the > estimate won't be influenced by the use of that comparison. The red star is 113 SE. With B-V>2.0 Its debatable whether or not very red stars are better comps than more "white" B-V<0.7 stars for red variables, but for sure mixing very red with white stars as comps, without indicating their color, results in increased "noise" in observations, since observers will select the different color comp stars randomly and thus the estimate will vary more than if all the comp stars were either all white or all red. The charts should all be corrected to use comps of similar B-V. If thats not possible, then at least their B-V should be marked on the chart, or some indication made of unusually red comps, and observers should be cautioned that only similar B-V comps should be used for making estimates. Mike Linnolt
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