Stellar Activity and the Strömgren Photometric Metallicity Calibration of Intermediate‐Type Dwarf Stars

• Published in: Publications of the Astronomical Society of the Pacific Vol. 116; no. 824; pp. 920 - 925
• Main Authors: Martell, Sarah L., Smith, Graeme H.
• Format: Journal Article
• Language: English
• Published: Chicago, IL The University of Chicago Press 01.10.2004; University of Chicago Press
• Subjects: Calibration; Coefficients; Error rates; Metal abundance; Spectroscopy; Standard deviation; Stars; Stellar activity; Stellar luminosities; Stromgren photometric system; Stellar activity; Metallicity; Dwarf stars
• ISSN: 0004-6280; 1538-3873
• DOI: 10.1086/425258

We consider the effect of stellar activity, as measured by X‐ray luminosity, on metallicities of solar‐neighborhood F and G dwarfs derived from Strömgren photometry. Rocha‐Pinto & Maciel found evidence that Strömgren colors systematically underpredict [Fe/H] for stars with extremely high CaiiH and K emission. We investigate whether a recent photometric metallicity calibration derived by Martell & Laughlin might be subject to this effect, and whether the amount of underprediction could reliably be expressed as a function of \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} \landscape $\mathrm{log}\,( L_{\mathrm{X}\,}/ L_{\mathrm{bol}\,}) $ \end{document} . Among those calibration stars used by Martell & Laughlin that are also in the Bright Star Catalogue and are detected in theROSATAll‐Sky Survey, there is no evidence for a correlation between photometric metallicity and stellar activity. However, many of the “very active stars” on which the Rocha‐Pinto & Maciel result was based are members of interacting binaries or are very young in age and are not included in the X‐ray sample that we are using. Among normal dwarf stars, it appears that stellar activity has little effect on the metallicity calibration of Strömgren colors.