Supernova properties in radio strongly depend on their circumstellar environment and they are an important probe to investigate the mass loss of supernova progenitors. Recently, core-collapse observations have been assembled rise time peak luminosity distribution supernovae at 8.4 GHz has estimated. In this paper, we constrain mass-loss prescriptions for red supergiants by using Type II radio. ...

We present new determinations of the blue to red supergiant ratio (B/R) in young open clusters at various metallicities. For this purpose, we examine the HR diagrams of 45 clusters in the Galaxy and of 4 clusters in the Magellanic Clouds. The identification of supergiants is based on spectroscopic measurements (with photometric counts to check the results). The new counts confirm the increase o...

Two peculiar galactic supergiants have been monitored in photometry and radial velocity during more than 15 years, using the telescopes of Geneva Observatory at La Silla (ESO, Chile) and Haute-Provence Observatory (France). These two supergiants are found to be the classical cepheids with the longest (V810 Cen) and shortest (V473 Lyr) periods in our Galaxy, i.e. 153 d and 1.5 d. In addition, V8...

Abstract Fast yellow pulsating supergiants (FYPS) are a recently discovered class of evolved massive pulsators. As candidate supergiant objects, and one the few classes stars, these objects have incredible potential to change our understanding structure evolution stars. Here we examine lightcurves sample 126 cool in Magellanic Clouds observed by Transiting Exoplanet Survey Satellite order ident...

The quantitative analysis of low resolution spectra of A and B supergiants is used to determine a distance modulus of 24.99± 0.10 mag (995± 46 Kpc) Based on VLT observations for ESO Large Programme 171.D-0004.

We present the second paper of a series whose aim is to perform a global study of Galactic A-supergiants. Very little work has been carried out to determine the stellar parameters of these stars. This is illustrated with a brief review of some previous works. In this paper we analyze the determination of absolute magnitudes, spectral types and atmospheric parameters using the most recent Kurucz...