Search Publications
The environment around young eruptive stars. SPHERE/IRDIS polarimetric imaging of seven protostars
Hales, A.; Ginski, C.; Garufi, A. +11 more
Aims: Eruptive stars are a class of young stellar objects that show an abrupt increase in luminosity. These burst-like episodes are thought to dominate the stellar accretion process during the Class 0 to Class I stage. We present an overview of a survey of seven episodically accreting protostars carried out to study their potentially complex …
The elusive atmosphere of WASP-12 b. High-resolution transmission spectroscopy with CARMENES
López-Puertas, M.; Nagel, E.; Amado, P. J. +19 more
To date, the hot Jupiter WASP-12 b has been the only planet with confirmed orbital decay. The late F-type host star has been hypothesized to be surrounded by a large structure of circumstellar material evaporated from the planet. We obtained two high-resolution spectral transit time series with CARMENES and extensively searched for absorption sign…
Pulsation modeling of the Cepheid Y Ophiuchi with RSP/MESA. Impact of the circumstellar envelope and a high projection factor on the Baade-Wesselink method
Smolec, R.; Moskalik, P.; Hocdé, V. +2 more
Context. Y Ophiuchi (Y Oph) is a classical Cepheid with a pulsation period of P = 17.12 days. This star is reported to be as dim as a Cepheid of about half its pulsation period and it exhibits a low radial velocity and light-curve amplitude. For these reasons, Y Oph is not used to calibrate period-luminosity (PL) relation and its distance remains …
A sub-Earth-mass planet orbiting Barnard's star
Bouchy, F.; Rebolo, R.; Allende Prieto, C. +37 more
Context. ESPRESSO guaranteed time observations (GTOs) at the 8.2m VLT telescope were performed to look for Earth-like exoplanets in the habitable zone of nearby stars. Barnard's star is a primary target within the ESPRESSO GTO as it is the second closest neighbour to our Sun after the α Centauri stellar system. Aims. We present here a large set of…
The radiative and dynamical impact of clouds in the atmosphere of the hot Jupiter WASP-43 b
Millour, E.; Spiga, A.; Bézard, B. +6 more
Context. Hot Jupiters are tidally locked gaseous exoplanets that exhibit large day-night temperature contrasts. Their cooler nightsides are thought to host clouds, as has been suggested by numerous observations. However, the exact nature of these clouds, their spatial distribution, and their impact on atmospheric dynamics, thermal structure, and s…
Nine lensed quasars and quasar pairs discovered through spatially extended variability in Pan-STARRS
Anguita, Timo; Courbin, Frédéric; Hempel, Angela +7 more
We present the proof of concept of a method for finding strongly lensed quasars using their spatially extended photometric variability through difference imaging in cadenced imaging survey data. We applied the method to Pan-STARRS, starting with an initial selection of 14 107 Gaia multiplets with quasar-like infrared colours from WISE. We identifi…
A second view on the X-ray polarization of NGC 4151 with IXPE
Bianchi, S.; Done, C.; Petrucci, P. -O. +21 more
We report on the second observing program of the active galactic nucleus NGC 4151 with simultaneous Imaging X-ray Polarimetry Explorer (IXPE; 750 ks), NuSTAR (∼60 ks), XMM-Newton (∼75 ks), and NICER (∼65 ks) pointings. NGC 4151 is the first Type-1 radio-quiet Seyfert galaxy with constrained polarization properties for the X-ray corona. Despite the…
Structure formation with primordial black holes to alleviate early star formation tension revealed by JWST
Padilla, N.; Colazo, P. E.; Stasyszyn, F.
Context. This Letter explores the potential role of primordial black holes (PBHs) to address cosmological tensions as the presence of more massive than expected galaxies at high redshifts, as indicated by recent James Webb Space Telescope observations.
Aims: Motivated by inflation models that enhance the power at scales beyond the observable …
Ultra-low-frequency LOFAR spectral indices of cluster radio halos
Di Gennaro, G.; Brunetti, G.; Tasse, C. +12 more
Context. A fraction of galaxy clusters harbor diffuse radio sources known as radio halos. The prevailing theory regarding their formation is based on second-order Fermi reacceleration of seed electrons caused by merger-driven turbulence in the intra-cluster medium. This mechanism is expected to be inefficient, which implies that a significant frac…
A long-period transiting substellar companion in the super-Jupiters to brown dwarfs mass regime and a prototypical warm-Jupiter detected by TESS
Trifonov, Trifon; Henning, Thomas; Triaud, Amaury H. M. J. +48 more
We report on the confirmation and follow-up characterization of two long-period transiting substellar companions on low-eccentricity orbits around TIC 4672985 and TOI-2529, whose transit events were detected by the TESS space mission. Ground-based photometric and spectroscopic follow-up from different facilities, confirmed the substellar nature of…