A Non-Detection of Red Supergiant Convection in Gaia
arXiv:2206.09926 · doi:10.1093/mnras/stac2780
Abstract
Large scale surface convection on red supergiants (RSGs) can lead to shifts in the photocenter of the star which might be measured by Gaia and used as a new probe of the surface dynamics of these rare but important stars. Unlike brightness variations, photocenter motions would provide information on the physical scale of the convective cells. The signal would be that RSGs show an excess astrometric noise at the level of a few percent of the stellar radius. Unfortunately, we find that the excess astrometric noise level of Gaia EDR3 is roughly an order of magnitude too large to detect the predicted motions and that RSGs have excess astrometric noise indistinguishable from other stars of similar magnitude and parallax. The typical excess astrometric noise steadily decreases with G magnitude (for G<11 mag), so it is crucial to compare stars of similar brightness.
5 pages, submitted to MNRAS
References in corpus (9)
- The Gaia mission
- Gaia Early Data Release 3: The astrometric solution
- The death of massive stars - I. Observational constraints on the progenitors of type II-P supernovae
- What causes the large extensions of red-supergiant atmospheres? Comparisons of interferometric observations with 1-D hydrostatic, 3-D convection, and 1-D pulsating model atmospheres
- Numerical Simulations of Convective 3-Dimensional Red Supergiant Envelopes
- Supernova Progenitors, Their Variability, and the Type IIP Supernova ASASSN-16fq in M66
- A catalog of known Galactic K-M stars of class I, candidate RSGs, in Gaia DR2
- Three-dimensional imaging of convective cells in the photosphere of Betelgeuse
- Probing Red Supergiant dynamics through photo-center displacements measured by Gaia