In astronomy, the Vaughan–Preston gap refers to the absence of F-, G- and K-type stars with intermediate levels of magnetic activity. That is, Vaughan and Preston noted [when?] two groups of stars with either high or low levels of activity, separated by an apparent gap.[1] There remains no consensus on the cause of the gap.[2]
References
^Vaughan, A. H.; Preston, G. W. (1980), "A survey of chromospheric CA II H and K emission in field stars of the solar neighborhood", Publications of the Astronomical Society of the Pacific, 92: 385, Bibcode:1980PASP...92..385V, doi:10.1086/130683
