Related papers: Two Decades of Hypergiant Research

The yellow supergiant content of nearby galaxies can provide a critical test of stellar evolution theory, bridging the gap between the hot, massive stars and the cool red supergiants. But, this region of the color-magnitude diagram is…

The simple physics of microlensing provides a well-understood tool with which to probe the atmospheres of distant stars in the Galaxy and Local Group with high magnification and resolution. Recent results in measuring stellar surface…

We explore the dynamics and evolution of the Universe at early and late times, focusing on both dark energy and extended gravity models and their astrophysical and cosmological consequences. Modified theories of gravity not only provide an…

Over the last third of the century, a few tens of events, detected by ground-based cosmic ray detectors, have opened a new window in the field of high-energy astrophysics. These events have macroscopic energies, unobserved sources, an…

Based on the data of spectral monitoring of the yellow hypergiant V509 Cas performed in 1996-2018 at the 6-m telescope with the spectral resolution of R$\ge$60 000, we studied in detail its kinematic state at various levels of extended…

The method and results of the computation of the model atmospheres and spectral energy distributions of chemically peculiar stars, are discussed. The models are computed with a special consideration of the particular problems encountered…

High resolution optical spectra of 57 Galactic B-type supergiant stars have been analyzed to determine their rotational and macroturbulent velocities. In addition, their atmospheric parameters (effective temperature, surface gravity and…

B[e] supergiants and yellow hypergiants share a number of common properties regarding their circumstellar environments. Using the forbidden [O I] and [Ca II] lines as disk tracers, we suggest the presence of a Keplerian disk or ring around…

Seismic data obtained with the space photometric CoRoT and Kepler instruments have led to a unprecendently precise characterization -- in terms of masses and ages -- of a large sample of post main sequence stars (low mass subgiant and red…

The empirical evidence for an upper mass limit for the red supergiant (RSG) progenitors of the Type II-P SNe at about 18 Msun, raises questions about the fate of the most luminous, most massive RSGs. These stars may evolve back to warmer…

Strongly irradiated exoplanets develop extended atmospheres that can be utilized to probe the deeper planet layers. This connection is particularly useful in the study of small exoplanets, whose bulk atmospheres are challenging to…

B[e] Supergiants are a phase in the evolution of some massive stars for which we have observational evidence but no predictions by any stellar evolution model. The mass-loss during this phase creates a complex circumstellar environment with…

A brief summary of some highlights in the study of high energy astrophysical sources over the past decade is presented. It is argued that the great progress that has been made derives largely from the application of new technology to…

Gravitational microlensing provides a new technique for studying the surfaces of distant stars. Microlensing events are detected in real time and can be followed up with precision photometry and spectroscopy. This method is particularly…

This paper provides a critical discussion of the observational evidence for winds in our own Galaxy, in nearby star-forming and active galaxies, and in the high-redshift universe. The implications of galactic winds on the formation and…

We investigate the character and role of convection in the atmosphere of a prototypical red giant located close to the red giant branch (RGB) tip with atmospheric parameters, Teff=3660K, log(g)=1.0, [M/H]=0.0. Differential analysis of the…

I present an overview of past, present and future research on microquasars and jets, showing that microquasars, i.e. galactic jet sources, are among the best laboratories for high energy phenomena. After remindind the analogy with quasars,…

The field of exoplanets is quickly expanding from just the detection of new planets and the measurement of their most basic parameters, such as mass, radius and orbital configuration, to the first measurements of their atmospheric…

Convection and turbulence in stellar atmospheres have a significant effect on the emergent flux from late-type stars. The theoretical advancements in convection modelling over recent years have proved challenging for the observers to obtain…

Context. Astrophysical jets are ubiquitous in the Universe on all scales, but their large-scale dynamics and evolution in time are hard to observe since they usually develop at a very slow pace. Aims. We aim to obtain the first…