The effects of differential rotation on the spectral energy distribution and line profiles of the rapidly rotating star alpha Oph

Abstract

The spectrum of the rapidly rotating star [alpha] Oph was modeled to examine the effect differential rotation has on its observed SED. Rotating stellar structure models were generated using the code ROTORC and constrained by the star’s interferometrically inferred parameters. The integrator code CLIC was used to calculate the SED of each model with an NLTE atmosphere (generated by the PHOENIX code) as it would be viewed at the inclination of [alpha] Oph. Comparison of the resultant synthetic SEDs and observations of the star revealed little difference between the goodness of fits of models with different rotation profiles due to the star’s inclination. Higher quality observations are necessary to further constrain the physical parameters and angular momentum distribution of [alpha] Oph but other previously observed rapidly rotating stars are current candidates for study with this technique.