RSGs are among the largest stars, with radii up to 1500 R ☉ and masses in the 10–25 M ☉ range (Levesque et al. As He-burning evolved stars, their surfaces present very cool effective temperatures between 34 K (spectral type of late-K to M) and average luminosities 20,000–300,000 L ☉ (Levesque et al. Red supergiants (RSGs) represent an important but still poorly characterized evolutionary phase of massive stars. Our results provide evidence for the presence of near-infrared spots representing about 3%–5% of the stellar flux. We find excellent agreement between the model-selection results and the reconstructions. The stellar surfaces are reconstructed by our model-independent imaging code SQUEEZE, making use of its novel regularizer based on Compressed Sensing theory. The effective surface temperatures are also determined and give further support to the recently derived hotter temperature scales of RSGs. Bayesian model selection is then used to determine the most probable number of spots. The stellar surfaces are first modeled as limb-darkened disks based on SATLAS models that fit both MIRC interferometric data and publicly available spectrophotometric data. We present here new techniques specially developed to analyze such cases, based on state-of-the-art statistical frameworks. The data show clear evidence of a departure from circular symmetry. mIRC 7.Two red supergiants (RSGs) of the Per OB1 association, RS Per and T Per, have been observed in the H band using the Michigan Infra-Red Combiner (MIRC) instrument at the CHARA array.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |