2016ApJ...832...68G -
Astrophys. J., 832, 68-68 (2016/November-3)
The orbit, rotation, and granulation of the G7 giant β Her.
GRAY D.F.
Abstract (from CDS):
The G7 IIIa single-lined spectroscopic binary, β Her, is studied with high-resolution, high-signal-to-noise spectra taken over 10 seasons from 23MR2000 to 10MY2009. Absolute radial velocities, corrected for convective blueshifts, are determined and new orbital parameters are derived. Line-depth ratios are used to measure temperature variation ∼2 K. A Fourier analysis is done for the line broadening, yielding a projected rotation velocity of 3.27 ± 0.20 km s–1 and a radial-tangential macroturbulence dispersion of 6.43 ± 0.08 km s–1. The "C" shaped bisector of Fe i λ6253 has its blue-most point at a relative flux level of 0.52, consistent with what is expected from β Her's absolute magnitude. The third-signature plot indicates granulation velocities 20% larger than the Sun's. Mapping the λ6253 line bisector onto the third-signature curve results in a flux deficit of 12.6 ± 1.0% that can be interpreted as arising from a temperature difference between granules and inter-granular lanes of 132 K. The flux deficit peaks near 5.5 km s–1 from the line center, suggesting the velocity difference between granules and lanes is ∼20% larger than that found for recently analyzed K giants.
Abstract Copyright:
© 2016. The American Astronomical Society. All rights reserved.
Journal keyword(s):
convection - line: profiles - stars: atmospheres - stars: late-type - Sun: granulation - techniques: spectroscopic - techniques: spectroscopic
Simbad objects:
5
Full paper
View the references in ADS
To bookmark this query, right click on this link: simbad:2016ApJ...832...68G and select 'bookmark this link' or equivalent in the popup menu