Related papers: Gaia-GIC-1: An Evolving Catastrophic Planetesimal …

I report on close encounters of stars to the Sun found in the first Gaia data release (GDR1). Combining Gaia astrometry with radial velocities of around 320 000 stars drawn from various catalogues, I integrate orbits in a Galactic potential…

Isolated HAEBE stars are believed to represent an intermediate stage of objects between young stellar objects surrounded by massive, optically thick, gaseous and dusty disks and Vega like stars surrounded by debris disks. The star AB Aur is…

A new class of pre-main sequence objects has been recently identified as pre-transitional disks. They present near-infrared excess coupled to a flux deficit at about 10 microns and a rising mid-infrared and far-infrared spectrum. These…

We report the discovery of mid-infrared excess emission in the young object RZ Psc. The excess constitutes ~8% of its Lbol, and is well fit by a single 500K black-body implying a dust free region within 0.7AU for optically thick dust. The…

RX~J1604.3-2130A is a young, dipper-type, variable star in the Upper Scorpius association, suspected to have an inclined inner disk with respect to its face-on outer disk. We study the eclipses to constrain the inner disk properties.We use…

We present Very Large Array observations at 3.5 cm of the nearby young star TW Hya that show the emission is constant in time over weeks, months and years, and spatially resolved with peak brightness temperature ~10 K at ~0.25 (15 AU)…

CG J1720-67.8 is an ultra compact group of several galaxies with a low velocity dispersion, and displaying the hallmarks of mutual interaction and possible tidal dwarf galaxy formation. In hierarchical models, the system is a possible…

We report the discovery of a unique object of uncertain nature -- but quite possibly a disintegrating asteroid or minor planet -- orbiting one star of the widely separated binary TIC 400799224. We initially identified the system in data…

In this contribution, we revisit the model of a dust-enshrouded star orbiting a low-luminosity galactic nucleus (Zaja\v{c}ek et al. 2014, 2016, 2017). Although it is quite challenging for dust to survive in hot X-ray-emitting plasma…

We present optical-infrared photometric and spectroscopic observations of Gaia18dvy, located in the Cygnus OB3 association at a distance of 1.88 kpc. The object was noted by the Gaia alerts system when its lightcurve exhibited a $\gtrsim$4…

The Herbig Ae/Be star LkHalpha 101 has been imaged at high angular resolution at a number of wavelengths in the near-infrared (from 1 to 3 microns) using the Keck 1 Telescope, and also observed in the mid-infrared (11.15 microns) using the…

The Gaia experiment recently reported the observation of a binary system composed of a Sun-like star orbiting a dark compact object, known as Gaia BH1. The nature of the compact object remains uncertain. While the Gaia mission identifies it…

We discuss the properties of several circumstellar debris disk systems imaged with the Hubble Space Telescope's Near Infrared Camera and Multi-Object Spectrometer in a survey of young stars with known far-IR excesses. These dusty disks…

We present an analysis of multi-wavelength observations of the dark globule DC\,314.8--5.1, using data from the Gaia optical, 2MASS near-infrared, and WISE mid-infrared surveys, dedicated imaging with the Spitzer Space Telescope, and X-ray…

Most of what we know about the formation of stars, and essentially everything we know about the formation of planets, comes from observations of our solar neighborhood within 2 kpc of the Sun. Before 2018, accurate distance measurements…

The high-precision astrometric mission GAIA recently reported the remarkable discovery of a Sun-like star closely orbiting a dark object, with a semi-major axis and period of $1.4\, \rm{AU}$ and $187.8$ days respectively. While the…

We present new observations, carried out with IRAM NOEMA, of the atomic neutral carbon transitions [CI](1-0) at 492 GHz and [CI](2-1) at 809 GHz of GN20, a well-studied star-bursting galaxy at $z=4.05$. The high luminosity line ratio…

We report the discovery of a circumstellar disk around the young A0 star, HR 4796, in thermal infrared imaging carried out at the W.M. Keck Observatory. By fitting a model of the emission from a flat dusty disk to an image at lambda=20.8…

[abridged] We present multi-epoch high-resolution optical spectroscopy, UV/radio/X-ray imaging, and archival Hubble and Spitzer observations of an intermediate luminosity optical transient recently discovered in the nearby galaxy NGC300. We…

We have identified four circumstellar disks with a deficit of dust emission from their inner 15-50 AU. All four stars have F-G spectral type, and were uncovered as part of the Spitzer Space Telescope ``Cores to Disks'' Legacy Program…