Related papers: Betelgeuse and the red supergiants

The $\sim$$2100$d Long Secondary Period of Betelgeuse's optical lightcurve and radial velocity motivated the prediction of a low-mass stellar companion, expected to be at maximal apparent separation from Betelgeuse around December 2024. We…

I review selected current observations of distant galaxies and our interpretation of the fragile (and occasionally contradictory) data. Galaxies at the ``contemporary limit'' of technology and redshift (z~6) are difficult to locate in the…

The distant ice giants of the Solar System, Uranus and Neptune, have only been visited by one space mission, Voyager 2. The current knowledge on their composition remains very limited despite some recent advances. A better characterization…

Top of the wish list of any astronomer who wants to understand galaxy formation and evolution is to resolve the stellar populations of a sample of giant elliptical galaxies: to take spectra of the stars and make Colour-Magnitude Diagrams…

The advent of the Spitzer Space Telescope has revolutionized our understanding of the history of star formation and galaxy mass assembly in the Universe. The tremendous leap in sensitivity from previous mid-to-far IR missions has allowed…

The nearby galaxies of the Local Group can act as our laboratories in helping to bridge the gap between theory and observations. In this review we will describe the complications of identifying samples of OB stars, yellow and red…

The wealth of data collected in the last few years thanks to the Pierre Auger Observatory and recently to the Telescope Array made the problem of the origin of ultra high energy cosmic rays a genuinely experimental/observational one. The…

Yellow supergiants (YSGs) are rare and poorly understood, and studying them is critical to constraining massive star evolution. We obtained flux-calibrated Magellan Inamori Kyocera Echelle (MIKE) high-resolution spectra of 40 YSGs in the…

The last 20 years have seen an explosion in our understanding of the large-scale distribution and motions of galaxies in the nearby universe. The field has moved from a largely qualitative, morphological description of the structures seen…

Near-infrared images are used to investigate the brightest red stars in the disk of the nearby spiral galaxy M81. Red supergiants (RSGs) form a well-defined sequence on the color-magnitude diagrams (CMDs) that peaks near M_K = -11.5; RSGs…

We present results from the occultation of Betelgeuse by asteroid (319) Leona on December 12, 2023, observed using a 64x64 pixel Single-Photon Avalanche Diode (SPAD) array mounted on a 10-inch telescope at the AstroCamp Observatory in…

Red Supergiants (RSGs) are cool (~4000K), highly luminous stars (L - 10^5 Lsun), and are among the brightest near-infrared (NIR) sources in star-forming galaxies. This makes them powerful probes of the properties of their host galaxies,…

Context. The interaction between stellar winds and the interstellar medium (ISM) can create complex bow shocks. The photometers on board the Herschel Space Observatory are ideally suited to studying the morphologies of these bow shocks.…

We report the discovery of two z ~ 12 galaxy candidates with unusually red UV slopes (betaUV ~> -1.5), and probe the origin of such colors at cosmic dawn. From Prospector fits to the UNCOVER/MegaScience dataset -- deep JWST/NIRCam imaging…

B[e] stars are among the most peculiar objects in the sky. This spectral type, characterised by allowed and forbidden emission lines, and a large infrared excess, does not represent an homogenous class of objects, but instead, a mix of…

Our understanding of how the Galaxy was formed and evolves is severely hampered by the lack of precise constraints on basic stellar properties such as distances, masses, and ages. Here, we show that solar-like pulsating red giants represent…

The Milky Way is the only galaxy for which we can resolve individual stars at all evolutionary phases, from the Galactic center to the outskirt. The last decade, thanks to the advent of near IR detectors and 8 meter class telescopes, has…

Olivier Chesneau challenged several fields of observational stellar astrophysics with bright ideas and an impressive amount of work to make them real in the span of his career, from his first paper on P Cygni in 2000, up to his last one on…

Although the universe at redshifts greater than six represents only the first one billion years (<10%) of cosmic time, the dense nature of the early universe led to vigorous galaxy formation and evolution activity which we are only now…

How do galaxies form and evolve? This is one of the most puzzling questions in astronomy. Galaxy assembly takes place throughout the entire history of the Universe, but our understanding of it is hampered by the unfortunate fact that we can…