相关论文: Modeling Stellar Surface Features on Subgiant Star…
Planetary radii are derived for 218 exoplanets orbiting 161 M dwarf stars. Stellar radii are based on an analysis of APOGEE high-resolution near-IR spectra for a subsample of the M-dwarfs; these results are used to define a stellar…
We analyzed the behavior of the rotational velocity in the parent stars of extrasolar planets. Projected rotational velocity v sin i and angular momentum were combined with stellar and planetary parameters, for a unique sample of 147 stars,…
We present StarryStarryProcess, a novel hierarchical Bayesian framework for mapping stellar surfaces using exoplanet transit light curves. While previous methods relied solely on stellar rotational light curves -- which contain limited…
Context. The Kepler mission has recently discovered a brown dwarf companion transiting one member of the M4V+M5V visual binary system LHS 6343 AB with an orbital period of 12.71 days. Aims. The particular interest of this transiting system…
In this PhD dissertation, I discuss issues of the Radial Velocities (RV) and transit methods. These techniques allow us to derive the mass and radius of an exoplanet, necessary to model its bulk structure and to have insight on its…
Stellar activity causes difficulties in the characterization of transiting exoplanets. Studies have been performed to quantify its impact on infrared interferometry, but not in the visible domain, which however allows reaching better…
In this work the latitude dependent stellar spot rotation is investigated based on dynamo models. The maps of the magnetic pressure at the surface from the dynamo calculations are treated similarly to the temperature maps obtained using…
Stellar spots may in some cases produce radial velocity (RV) signatures similar to those of exoplanets. To further investigate the impact of spots, we aim at studying the detectability of Earth mass planets in the habitable zone (HZ) of…
Most extrasolar planets have been detected by their influence on their parent star, typically either gravitationally (the Doppler method) or by the small dip in brightness as the planet blocks a portion of the star (the transit method).…
We analyzed the behavior of the rotational velocity in the parent stars of extrasolar planets. Projected rotational velocity v sin i and angular momentum were combined with stellar and planetary parameters, for a unique sample of 147 stars,…
Dark spots on the surface of active stars produce changes in the shapes of the spectral lines that mimic spurious Doppler shifts, compromising the detection of small planets by means of the radial velocity (RV) technique. Modelling the…
The Doppler method of exoplanet detection has been extremely successful, but suffers from contaminating noise from stellar activity. In this work a model of a rotating star with a magnetic field based on the geometry of the K2 star Epsilon…
Accounting for stellar activity is a crucial component of the search for ever-smaller planets orbiting stars of all spectral types. We use Doppler imaging methods to demonstrate that starspot induced radial velocity variability can be…
In recent years, analyses of eclipsing binary systems have unveiled differences between the observed fundamental properties of low-mass stars and those predicted by stellar structure models. Particularly, radius and effective temperatures…
The space telescope CoRoT has provided light curves of T Tauri stars belonging to the star-forming region of NGC 2264 with unprecedented continuity and precision in the framework of a coordinated multi-wavelength observational project. We…
In this study we present simultaneous low-resolution longitudinal magnetic field measurements and high-resolution spectroscopic observations of the cool single giant FK Com. The variation of the magnetic field over the rotational period of…
We analyze the correlation between starspots and superflares on solar-type stars using observations from the Kepler mission. The analysis shows that the observed fraction of stars with superflares decreases as the rotation period increases…
We report on a new method for tracking the phases of the orbital modulations in very short-period, near-contact, and contact binary systems systems in order to follow starspots. We apply this technique to Kepler light curves for 414 binary…
We perform an in-depth analysis of the recently validated TOI-3884 system, an M4 dwarf star with a transiting super-Neptune. Using high precision light curves obtained with the 3.5 m Apache Point Observatory and radial velocity observations…
Stellar magnetic activity is governed by the interplay between rotation, convection, and the evolution of surface magnetic structures, yet the role of planetary systems in shaping these processes remains uncertain. Here, we analyze…