Related papers: A Model-Independent Mass and Moderate Eccentricity…
To fully constrain the orbits of low mass circumstellar companions, we conduct combined analyses of the radial velocity data as well as the Gaia and Hipparcos astrometric data for eight nearby systems. Our study shows that companion-induced…
I have used the third data release of the Gaia mission to improve the reliability and completeness of membership samples in the beta Pic moving group (BPMG) and other nearby associations with ages of 20-50 Myr (Sco Body, Carina, Columba,…
The chemically peculiar B star $\phi$ Phe was, until very recently, considered a triple system, even though the data were not conclusive and the orbits rather uncertain. Very recent results by Korhonen et al. (2013) provided a revised…
We aim at resolving the circumstellar environment around beta Pic in the near-infrared in order to study the inner planetary system (< 200 mas, i.e., ~4 AU). Precise interferometric fringe visibility measurements were obtained over seven…
Here we show that the ~10 Myr Beta Pictoris system hosts a massive giant planet, Beta Pictoris b, located 8 to 15 AU from the star. This result confirms that gas giant planets form rapidly within disks and validates the use of disk…
Stellar mass is a fundamental parameter that is key to our understanding of stellar formation and evolution, as well as the characterization of nearby exoplanet companions. Historically, stellar masses have been derived from long-term…
Precise exoplanet characterization requires precise classification of exoplanet host stars. The masses of host stars are commonly estimated by comparing their spectra to those predicted by stellar evolution models. However,…
We present detailed modelling of the exoplanet-host star Mu Arae, using a new method for the asteroseismic analysis, and taking into account the new value recently derived for the Hipparcos parallax. The aim is to obtain precise parameters…
About 4" south of the young A0-type star HR 7329, a faint companion candidate was found by Lowrance et al. (2000). Its spectral type of M7-8 is consistent with a young brown dwarf companion. Here, we report ten new astrometric imaging…
Main-sequence stars with convective envelopes often appear larger and cooler than predicted by standard models of stellar evolution for their measured masses. This is believed to be caused by stellar activity. In a recent study, accurate…
Determination of an exoplanet's mass is a key to understanding its basic properties, including its potential for supporting life. To date, mass constraints for exoplanets are predominantly based on radial velocity (RV) measurements, which…
Context: The space telescope Gaia is dedicated mainly to performing high-precision astrometry, but also spectroscopy and epoch photometry which can be used to study various types of photometric variability. One such variability type is…
Ultra-precise astrometry from the Gaia mission is expected to lead to astrometric detections of more than 20,000 exoplanets in our Galaxy. One of the factors that could hamper such detections is the astrometric jitter caused by the magnetic…
We combine absolute astrometry from Hipparcos and Gaia with archival radial velocities from the Keck/HIRES and ESO/HARPS spectrographs, as well as relative astrometry (when available), to derive masses and orbits for 156 companions around…
We present Keck images of the dust disk around Beta Pictoris at 17.9 microns that reveal new structure in its morphology. Within 1" (19 AU) of the star, the long axis of the dust emission is rotated by more than 10 degrees with respect to…
The nearby young star beta Pictoris hosts a rich and complex planetary system, with at least two giant planets and a nearly edge-on debris disk that contains several dynamical subpopulations of planetesimals. While the inner ranges of the…
As part of our ongoing NTT SoFI survey for variability in young free-floating planets and low mass brown dwarfs, we detect significant variability in the young, free-floating planetary mass object PSO J318.5-22, likely due to rotational…
The circumstellar disk of PDS 70 hosts two forming planets, which are actively accreting gas from their environment. In this work, we report the first detection of PDS 70 b in the Br$\alpha$ and $M'$ filters with VLT/NACO, a tentative…
The synergy between different detection methods is a key asset in exoplanetology, allowing for both precise characterization of detected exoplanets and robust constraints even in the case of non-detection. Recently, the interplay between…
We use data from the Hipparcos Catalog and the Barbier-Brossat & Figon (2000) catalog of stellar radial velocities to test the hypothesis that the Beta Pic planetesimal disk was disrupted by a close stellar encounter. We trace the space…