Search Publications
A large range of haziness conditions in hot-Jupiter atmospheres
Lavvas, Panayotis; Arfaux, Anthony
We present a study of photochemical hazes of exoplanet atmospheres based on a self-consistent model including haze microphysics, disequilibrium chemistry, and radiative feedbacks. We derive the haze properties required to match Hubble Space Telescope observations of 10 hot-Jupiters. HAT-P-12b, HD-189733b, HD-209458b, and WASP-6b require haze mass …
Evidence in favour of density wave theory through age gradients observed in star formation history maps and spatially resolved stellar clusters
Davis, Benjamin L.; Eufrasio, Rafael; Monson, Erik B. +7 more
Quasi-stationary density wave theory predicts the existence of an age gradient across the spiral arms with a phase crossing at the corotation radius. We have examined evidence for such age gradients using star formation history (SFH) maps derived from LIGHTNING, a spectral energy distribution fitting procedure, and by using spatially resolved stel…
Combined spectroscopy and intensity interferometry to determine the distances of the blue supergiants P Cygni and Rigel
Domiciano de Souza, A.; Vakili, F.; Rivet, J. -P. +10 more
In this paper, we report on spatial intensity interferometry measurements within the Hα line on two stars: the Luminous Blue Variable supergiant P Cygni and the late-type B supergiant Rigel. The experimental setup was upgraded to allow simultaneous measurement of two polarization channels, instead of one in our previous setup, and the zero baselin…
TOI-2046b, TOI-1181b, and TOI-1516b, three new hot Jupiters from TESS: planets orbiting a young star, a subgiant, and a normal star
Latham, David W.; Cochran, William D.; Endl, Michael +54 more
We present the confirmation and characterization of three hot Jupiters, TOI-1181b, TOI-1516b, and TOI-2046b, discovered by the TESS space mission. The reported hot Jupiters have orbital periods between 1.4 and 2.05 d. The masses of the three planets are 1.18 ± 0.14 MJ, 3.16 ± 0.12 MJ, and 2.30 ± 0.28 MJ, for TOI-11…
Stellar proper motions in the outskirts of classical dwarf spheroidal galaxies with Gaia EDR3
Pace, Andrew B.; Zivick, Paul; Riley, Alexander H. +2 more
We use Gaia EDR3 data to identify stars associated with six classical dwarf spheroidals (dSphs) (Draco, Ursa Minor, Sextans, Sculptor, Fornax, Carina) at their outermost radii, beyond their nominal King stellar limiting radius. For all of the dSphs examined, we find radial velocity matches with stars residing beyond the King limiting radius and wi…
Discovery of hot subdwarfs covered with helium-burning ash
Werner, Klaus; Reindl, Nicole; Geier, Stephan +1 more
Helium-rich subdwarf O stars (sdOs) are hot compact stars in a pre-white dwarf evolutionary state. Most of them have effective temperatures and surface gravities in the range Teff = 40 000-50 000 K and log g = 5.5-6.0. Their atmospheres are helium dominated. If present at all, C, N, and O are trace elements. The abundance patterns are e…
Kinematics of the molecular interstellar medium probed by Gaia: steep velocity dispersion-size relation, isotropic turbulence, and location-dependent energy dissipation
Li, Guang-Xing; Chen, Bing-Qiu; Zhou, Ji-Xuan
The evolution of the molecular interstellar medium is controlled by processes such as turbulence, gravity, stellar feedback, and Galactic shear. AL a part of the ISM-6D project, using Gaia astrometric measurements towards a sample of young stellar objects (YSOs), we study the morphology and kinematic structure of the associated molecular gas. We i…
Distance and age of the massive stellar cluster Westerlund 1. I. Parallax method using Gaia-EDR3
Damineli, Augusto; Navarete, Felipe; Almeida, Leonardo A. +2 more
Westerlund 1 (Wd 1) is one of the most massive young star clusters in the Milky Way. Although relevant for star formation and evolution, its fundamental parameters are not yet very well constrained. We aim to derive an accurate distance and provide constraints on the cluster age. We used the photometric and astrometric information available in the…
The OmegaWhite survey for short-period variable stars - VII. High amplitude short-period blue variables
Ramsay, Gavin; Buckley, David A. H.; Kupfer, Thomas +11 more
Blue Large-Amplitude Pulsators (BLAPs) are a relatively new class of blue variable stars showing periodic variations in their light curves with periods shorter than a few tens of minutes and amplitudes of more than 10 per cent. We report nine blue variable stars identified in the OmegaWhite survey conducted using ESO's VST, which shows a periodic …
The tidal evolution of the Fornax dwarf spheroidal and its globular clusters
Fattahi, Azadeh; Navarro, Julio F.; Errani, Raphaël +2 more
The dark matter content of the Fornax dwarf spheroidal galaxy inferred from its kinematics is substantially lower than expected from LCDM cosmological simulations. We use N-body simulations to examine whether this may be the result of Galactic tides. We find that, despite improved proper motions from the Gaia mission, the pericentric distance of F…