Related papers: Spin-orbit alignment and magnetic activity in the …

The presence of giant gaseous planets that reside in close proximity to their host stars may be a consequence of large-scale radial migration through the proto-planetary nebulae. Within the context of this picture, significant orbital…

Using spectropolarimetry, we investigate the large-scale magnetic topologies of stars hosting close-in exoplanets. A small survey of ten stars has been done with the twin instruments TBL/NARVAL and CFHT/ESPaDOnS between 2006 and 2011. Each…

The obliquity between the stellar spin axis and the planetary orbit, detected via the Rossiter-McLaughlin (RM) effect, is a tracer of the formation history of planetary systems. While obliquity measurements have been extensively applied to…

Direct-imaging exoplanet surveys have discovered a class of 5-20 \Mjup\space substellar companions at separations >100 AU from their host stars, which present a challenge to planet and star formation models. Detailed analysis of the orbital…

We report the analysis of the rotational properties of our sample of Herbig Ae/Be (HAeBe) and related stars for which we have obtained high-resolution spectropolarimetric observations. Using the projected rotational velocities measured at…

With a Jupiter-mass planet orbiting at a distance of only 0.031 AU, the active K2 dwarf HD 189733 is a potential candidate in which to study the magnetospheric interactions of a cool star with its recently-discovered close-orbiting giant…

V921 Scorpii is a close binary system (separation 0.025") showing the B[e]-phenomenon. The system is surrounded by an enigmatic bipolar nebula, which might have been shaped by episodic mass-loss events, possibly triggered by dynamical…

Chauvin et al. 2005 imaged a co-moving companion at ~260 AU from the young star AB Pic A. Evolutionary models predictions based on J H K photometry of AB Pic b suggested a mass of ~13 - 14 MJup, placing the object at the deuterium-burning…

The recently discovered spectroscopic binary $\rho$ Oph A is a rare magnetic hot binary system composed of two early B-type stars, comprising a non-magnetic primary (Aa) and a slightly less massive magnetic secondary (Ab). Using near-IR…

The angle between the stellar spin and the planetary orbit axes (spin-orbit angle) is supposed to carry valuable information on the initial condition of the planet formation and the subsequent migration history. Indeed current observations…

Magnetic early B-type stars are rare. To identify them, we use the strongest indirect indicator of a magnetic field in B stars, which is periodic variability of UV stellar wind lines occurring symmetric about the approximate rest…

Today, one of the greatest challenges concerning the Ap/Bp stars is to understand the origin of their slow rotation and their magnetic fields. The favoured hypothesis for the latter is the fossil field, which implies that the magnetic…

We report the sky-projected spin-orbit angle $\lambda$ for HD 191939 b, the innermost planet in a 6 planet system, using Keck/KPF to detect the Rossiter-McLaughlin (RM) effect. Planet b is a sub-Neptune with radius 3.4 $\pm$ 0.8…

We present theoretical predictions for photometric and spectroscopic signatures of rings around transiting extrasolar planets. On the basis of a general formulation for the transiting signature in the stellar light curve and the velocity…

We derive the effective temperatures and gravities of 461 OB stars in 19 young clusters by fitting the H-gamma profile in their spectra. We use synthetic model profiles for rotating stars to develop a method to estimate the polar gravity…

Two close-in planets have been recently found around the M-dwarf flare star AU Microscopii (AU Mic). These Neptune-sized planets (AU Mic b and c) seem to be located very close to the so-called "evaporation valley" in the exoplanet…

All four circumbinary (CB) protoplanetary disks orbiting short-period ($P < 20$ day) double-lined spectroscopic binaries (SB2s)---a group that includes UZ Tau E, for which we present new ALMA data---exhibit sky-plane inclinations $i_{\rm…

High energy X-ray and ultraviolet (UV) radiation from young stars impacts planetary atmospheric chemistry and mass loss. The active $\sim 22$ Myr M dwarf AU Mic hosts two exoplanets orbiting interior to its debris disk. Therefore, this…

We present new observations of a transit of the 111-day-period exoplanet HD80606b. Using the Spitzer Space Telescope and its IRAC camera on the post-cryogenic mission, we performed a 19-hour-long photometric observation of HD80606 that…

We report a spin-orbit misalignment for the hot-Jupiter HATS-14b, measuring a projected orbital obliquity of |lambda|= 76 -5/+4 deg. HATS-14b orbits a high metallicity, 5400 K G dwarf in a relatively short period orbit of 2.8 days. This…