Figure 3: Relationship between the signal-to-noise ratio in the blue part of the spectra and effective temperature.
From: Observational evidence for enhanced magnetic activity of superflare stars
The effective temperatures are from Brown et al.58 and the signal-to-noise ratio calculated as described by Luo et al.35 The 5,648 main-sequence stars with signal-to-noise ratio higher than 10, which we analyse in this study, are marked with red. A clear separation between main-sequence (around 6,000 K) and evolved stars (around 5,000 K) can be seen as a function of effective temperature.
