Observations of spectral line asymmetries and convective velocities in F, G, and K stars

Abstract

view Abstract Citations (121) References (20) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Observations of spectral line asymmetries and convective velocities in F, G and K stars. Gray, D. F. Abstract Line asymmetries are found to exist generally in F, G, and K stars. Line bisectors were measured for 11 relatively unblended lines in each of 27 stars, and an average line bisector was determined for each star. The average bisectors show systematic changes in velocity span and shape with spectral type. The bisector characteristics are interpreted in terms of granulation-type motion. Convective velocities are deduced as a function of spectral type. Values of approximately 3 times solar are seen in F5IV and V, in G0 III, and in K4 III stars. Minimum convective velocities occur near G8 with a value of approximately 0 for luminosity types IV and V but near the solar value for type III. The height of penetration of convection is found to be lowest in solar-type stars with convection essentially dying out before reaching the top of their photospheres. In nonsolar-type stars, larger convective velocities produce greater height penetration. Publication: The Astrophysical Journal Pub Date: April 1982 DOI: 10.1086/159818 Bibcode: 1982ApJ...255..200G Keywords: Convective Flow; F Stars; Flow Velocity; G Stars; K Stars; Line Spectra; Stellar Atmospheres; Stellar Luminosity; Stellar Spectra; Data Reduction; Hertzsprung-Russell Diagram; Photosphere; Stellar Temperature; Astronomy full text sources ADS | data products SIMBAD (28)