Related papers: The planetary system host HR\,8799: On its $\lambd…
HR8799 is orbited by at least four giant planets, making it a prime target for the recently commissioned Spectro-Polarimetric High-contrast Exoplanet REsearch (VLT/SPHERE). As such, it was observed on five consecutive nights during the…
A method for obtaining asteroseismological information of a Gamma Doradus oscillating star showing at least three pulsation frequencies is presented. This method is based on a first-order asymptotic g-mode expression, in agreement with the…
Comparing chemical abundances of a planet and the host star reveals the origin and formation path. Stellar abundance is measured with high-resolution spectroscopy. Planet abundance, on the other hand, is usually inferred from low-resolution…
We report the discovery of both intermediate-order gravity mode and low-order pressure mode pulsation in the same star, HD 209295. It is therefore both a gamma Doradus and a delta Scuti star, which makes it the first confirmed member of two…
Debates regarding the age and inclination of the planetary system orbiting HR 8799, and the release of additional astrometric data following the discovery of the fourth planet prompted us to examine the possibility of constraining these two…
Fast-rotating hot stars are challenging targets for exoplanet searches due to rotational broadening and stellar variability. Moreover, hot stars often exhibit pulsations, an additional source of scatter in both photometric and spectroscopic…
A system of four super-Jupiter planets around HR 8799 is the first multi-planet configuration discovered via the direct imaging technique. Despite over decade of research, the system's architecture remains not fully resolved. The main…
The TESS space mission provides us with high-precision photometric observations of bright stars over more than 70% of the entire sky, allowing us to revisit and characterise well-known stars. We aim to conduct an asteroseismic analysis of…
Rossby modes are the oscillations in a rotating fluid, whose restoring force is the Coriolis force. They provide an additional diagnostic to understand the rotation of stars, which complicates asteroseismic modelling. We report 82…
Based on 2-minute cadence TESS data, we investigate pulsations of TIC 65138566 and TIC 139729335 and discover them to be two new HADS stars with equally spaced g modes. We recognize the radial fundamental mode $f_1$ = 18.3334 c/d and the…
We have discovered both intermediate-order gravity mode and low-order pressure mode pulsation in the same star, HD 209295. It is therefore both a Gamma Doradus and a Delta Scuti star, which makes it the first pulsating star to be a member…
Photometric time series of the $\gamma$ Dor star 43 Cyg obtained with the BRITE-Constellation nano-satellites allow us to study its pulsational properties in detail and to constrain its interior structure. We aim to find a g-mode period…
Aims. To explore the chemical pattern of early-type stars with planets, searching for a possible signature of planet formation. In particular, we study a likely relation between the lambda Bootis chemical pattern and the presence of giant…
Recent advances in astronomical instrumentation mean that we are now able to image the thermal emission from the disks of dust around main sequence stars that may be the fossil remnants of planetary formation. These observations imply that…
Space asteroseismology reveals that stellar structure and evolution models of intermediate- and high-mass stars are in need of improvement in terms of angular momentum and chemical element transport. We aim to probe the interior structure…
We analyse the pulsating behaviour of TIC 308396022 observed by the TESS mission. The star is a high-amplitude $\delta$ Sct star (HADS) that shows a very rich amplitude spectrum using the 3-yr light curve. Among these frequencies, the…
The analysis of transiting extra-solar planets provides an enormous amount of information about the formation and evolution of planetary systems. A precise knowledge of the host stars is necessary to derive the planetary properties…
We present previously unpublished July 2005 $H$-band coronagraphic data of the young, planet-hosting star HR 8799 from the newly-released Keck/NIRC2 archive. Despite poor observing conditions, we detect three of the planetary companions (HR…
Gamma Doradus stars are excellent targets for asteroseismology since the gravity modes present in these stars probe the deep stellar interiors. Mode identification will improve the knowledge of these stars considerably. A selected group of…
Disk fragmentation resulting from the gravitational instability has been proposed as an efficient mechanism for forming giant planets. We use the planet Fomalhaut b, the triple-planetary system HR 8799, and the potential protoplanet…