The rotationally broadened line profiles of Sirius.
Abstract
Photospheric Fe I and Fe II absorption line profiles in Sirius are analyzed. The Fourier transforms of the line profiles reveal several sidelobes consistent with line broadening from rigid stellar rotation at V sin i = 15.3 + or - 0.3 km/s. The Fourier transforms are fitted, leading to deduced parameters of line profiles and stellar rotation. These profiles are remarkably similar to Gaussians with FWHM at about 8 km/s and resemble synthetic line profiles computed from hydrodynamic model atmospheres by Gigas (1989). The 'superposition' of neighboring absorption lines occasionally produces spectral features that are much narrower than the widths of individual rotationally broadened profiles. The widths of such 'subrotational' features may approach these of the 'intrinsic' line profiles, illustrating the need for very high spectral resolution to fully resolve the spectra also of rapidly rotating stars.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- October 1990
- Bibcode:
- 1990A&A...237..137D
- Keywords:
-
- Absorption Spectra;
- Line Spectra;
- Reference Atmospheres;
- Stellar Rotation;
- Astronomical Spectroscopy;
- Early Stars;
- Fourier Transformation;
- Stellar Atmospheres;
- Astrophysics