WILSON-BAPPU EFFECT: EXTENDED TO SURFACE GRAVITY

Journal Article · Tue Oct 01 04:00:00 EDT 2013 · Astronomical Journal (New York, N.Y. Online)

DOI:https://doi.org/10.1088/0004-6256/146/4/73· OSTI ID:22136528

Park, Sunkyung; Kang, Wonseok; Lee, Jeong-Eun ^[1]; Lee, Sang-Gak ^[2]

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1. School of Space Research, Kyung Hee University, Yongin-Si, Gyeonggi-Do 446-701 (Korea, Republic of)
2. Astronomy Program, Department of Physics and Astronomy, Seoul National University, Seoul 151-742 (Korea, Republic of)

In 1957, Wilson and Bappu found a tight correlation between the stellar absolute visual magnitude (M{sub V} ) and the width of the Ca II K emission line for late-type stars. Here, we revisit the Wilson-Bappu relationship (WBR) to claim that the WBR can be an excellent indicator of stellar surface gravity of late-type stars as well as a distance indicator. We have measured the width (W) of the Ca II K emission line in high-resolution spectra of 125 late-type stars obtained with the Bohyunsan Optical Echelle Spectrograph and adopted from the Ultraviolet and Visual Echelle Spectrograph archive. Based on our measurement of the emission line width (W), we have obtained a WBR of M{sub V} = 33.76 - 18.08 log W. In order to extend the WBR to being a surface gravity indicator, stellar atmospheric parameters such as effective temperature (T{sub eff}), surface gravity (log g), metallicity ([Fe/H]), and micro-turbulence ({xi}{sub tur}) have been derived from self-consistent detailed analysis using the Kurucz stellar atmospheric model and the abundance analysis code, MOOG. Using these stellar parameters and log W, we found that log g = -5.85 log W+9.97 log T{sub eff} - 23.48 for late-type stars.

• OSTI ID: 22136528
• Journal Information: Astronomical Journal (New York, N.Y. Online), Journal Name: Astronomical Journal (New York, N.Y. Online) Journal Issue: 4 Vol. 146; ISSN 1538-3881
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
DISTANCE
GRAVITATION
LINE WIDTHS
M CODES
RESOLUTION
STARS
STELLAR ATMOSPHERES
TURBULENCE
ULTRAVIOLET SPECTROMETERS
VISIBLE SPECTRA