LAZZONI , C.

Context. The frequency, semi-major axis, and mass distribution of stellar companions likely depend on the mass of the primaries and on the environment where the stars form. These properties are very different for early- and late-type stars. However, data are largely incomplete, even for the closest environments to the Sun, preventing a cleaner...

Context. Dusty debris disks around pre- and main-sequence stars are potential signposts for the existence of planetesimals and exoplanets. Giant planet formation is therefore expected to play a key role in the evolution of the disk. This is indirectly confirmed by extant submillimeter near-infrared images of young protoplanetary and cool dusty...

Aims: In this work, we aim to constrain the masses and separations of potential substellar companions to five accelerating stars (HIP 1481, HIP 88399, HIP 96334, HIP 30314, and HIP 116063) using multiple data sets acquired with different techniques. Methods: Our targets were originally observed as part of the SPHERE/SHINE survey, and radial...

Context. Debris disks are the intrinsic by-products of the star and planet formation processes. Most likely due to instrumental limitations and their natural faintness, little is known about debris disks around low mass stars, especially when it comes to spatially resolved observations. Aims: We present new VLT/SPHERE IRDIS dual-polarization...

Context. Observational data from space- and ground-based campaigns have revealed that the 10-30 Ma old V1298Tau star hosts a compact and massive system of four planets. Mass estimates are available for the two outer giant planets and point to unexpectedly high densities for their young ages. Aims: We investigate the formation of these two...

Aims: HR 2562 is an F5V star located at 33 pc from the Sun hosting a substellar companion that was discovered using the Gemini planet imager (GPI) instrument. The main objective of the present paper is to provide an extensive characterization of the substellar companion, by deriving its fundamental properties. Methods: We observed HR 2562 with...

Context. HR 8799 is a young planetary system composed of four planets and a double debris belt. Being the first multi-planetary system discovered with the direct imaging technique, it has been observed extensively since 1998. This wide baseline of astrometric measurements, counting over 50 observations in 20 years, permits a detailed orbital...

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We present the multiple stellar systems observed within the SpHere INfrared survey for Exoplanet (SHINE). SHINE searched for sub-stellar companions to young stars using high contrast imaging. Although stars with known stellar companions within the SPHERE field of view (< 5.5 arcsec) were removed from the original target list, we detected...

Context. The 51 Eridani system harbors a complex architecture with its primary star forming a hierarchical system with the binary GJ 3305AB at a projected separation of 2000 au, a giant planet orbiting the primary star at 13 au, and a low-mass debris disk around the primary star with possible cold and warm components inferred from the spectral...

Context. PDS 70 is a young (5.4 Myr), nearby (~113 pc) star hosting a known transition disk with a large gap. Recent observations with SPHERE and NACO in the near-infrared (NIR) allowed us to detect a planetary mass companion, PDS70b, within the disk cavity. Moreover, observations in H_alpha with MagAO and MUSE revealed emission associated to...

The nearby Herbig Be star HD 100546 is known to be a laboratory for the study of protoplanets and their relation with the circumstellar disk, which is carved by at least two gaps. We observed the HD 100546 environment with high-contrast imaging exploiting several different observing modes of SPHERE, including data sets with and without...