Synthetic spectra of red supergiants with winds

DOI

The rate at which mass is lost during the Red Supergiant evolutionary stage may strongly influence how the star appears. Though there have been many studies discussing how RSGs appear in the mid and far infrared (IR) as a function of their mass-loss rate, to date there have been no such investigations at optical and near-IR wavelengths. In a preliminary study we construct model atmospheres for RSGs which include a wind, and use these models to compute synthetic spectra from the optical to the mid-infrared. The inclusion of a wind has two important effects. Firstly, higher mass-loss rates result in stronger absorption in the TiO bands, causing the star to appear as a later spectral type despite its effective temperature remaining constant. This explains the observed relation between spectral type, evolutionary stage and mid-IR excess, as well as the mismatch between temperatures derived from the optical and infrared. Secondly, the wind mimics many observed characteristics of a 'MOLsphere', potentially providing an explanation for the extended molecular zone inferred to exist around nearby RSGs. Thirdly, we show that wind fluctuations can explain the spectral variability of Betelgeuse during its recent dimming, without the need for dust.

Identifier
DOI http://doi.org/10.26093/cds/vizier.75085757
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/MNRAS/508/5757
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/508/5757
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/508/5757
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/MNRAS/508/5757
Provenance
Creator Davies B.; Plez B.
Publisher CDS
Publication Year 2022
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Interdisciplinary Astronomy; Natural Sciences; Observational Astronomy; Physics; Stellar Astronomy