Friday, May 30, 2008
If two stars of two different spectral types have equal brightness in the V filter, then one would like to know what is the difference in flux over the Kepler bandpass for the two stars. One starts by defining that a G2V star will have equal brightness in the V filter and Kepler bandpass. This definition provides a natural way to scale the artificial spectra and to compute the flux difference in the V filter and Kepler bandpass as a function of spectral type. The Figure demonstrates how a hot A2V and cool M2V star with equal brightness in the V filter can have quite different brightnesses through the Kepler bandpass with extends to the near infrared part of the spectrum.