Related papers: From infall to rotation around young stellar objec…

We present stellar rotation rates derived from Transiting Exoplanet Survey Satellite (TESS) light curves for stars in Upper Centaurus-Lupus (UCL; ~136 pc, ~16 Myr) and Lower Centaurus-Crux (LCC; ~115 pc, ~17 Myr). We find spot-modulated…

Using Non-Redundant Mask interferometry (NRM), we searched for binary companions to objects previously classified as Transitional Disks (TD). These objects are thought to be an evolutionary stage between an optically thick disk and…

We have conducted ALMA cycle 2 observations in the 1.3 mm continuum and in the C18O (2-1) and SO (5_6-4_5) lines at a resolution of ~0.3" toward the Class 0 protostar B335. The 1.3 mm continuum, C18O, and SO emission all show central…

Star formation proceeds via the collapse of a molecular cloud core over multiple dynamical timescales. Turbulence within cores results in a spatially non-uniform angular momentum of the cloud, causing a stochastic variation in orientation…

The recently recognized class of "transitional disk" systems consists of young starswith optically-thick outer disks but inner disks which are mostly devoid of small dust. Here we introduce a further class of "pre-transitional disks" with…

Magnetospheric accretion has been thoroughly studied in young stellar systems with full non-evolved accretion disks, but it is poorly documented for transition disk objects with large inner cavities. We aim at characterizing the star-disk…

In young circumstellar disks, accretion--the inspiral of disk material onto the central star--is important for both the buildup of stellar masses and the outcome of planet formation. Although the existence of accretion is well documented,…

(abridged) Most Class II sources (of nearby star forming regions) are surrounded by disks with weak millimeter continuum emission. These "faint" disks may hold clues to the disk dissipation mechanism. We attempt to determine the…

Protostellar disks are a ubiquitous part of the star formation process and the future sites of planet formation. As part of the Early Planet Formation in Embedded Disks (eDisk) large program, we present high-angular resolution dust…

The projected stellar rotational velocity ($v \sin i$) is critical for our understanding of processes related to the evolution of angular momentum in pre-main sequence stars. We present $v \sin i$ measurements of high-resolution infrared…

We present a high spatial resolution, 10-20 micron survey of 65 T Tauri binary stars in Taurus, Ophiuchus, and Corona Australis using the Keck 10 m telescopes. Designed to probe the inner ~1 AU region of the circumstellar disks around the…

Motivated by the recent detection of a large number of embedded young stellar objects (YSOs) with mass accretion rates that are inconsistent with the predictions of the standard model of inside-out collapse (Shu 1977), we perform a series…

In the past few years, several disks with inner holes that are empty of small dust grains have been detected and are known as transitional disks. Recently, Spitzer has identified a new class of "pre-transitional disks" with gaps; these…

We find a trend between the mid-infrared HCN/H2O flux ratio and submillimeter disk mass among T Tauri stars in Taurus. While it may seem puzzling that the molecular emission properties of the inner disk (< few AU) are related to the…

Aims: Revealing the fragmentation, infall, and outflow processes in the immediate environment around massive young stellar objects is crucial for understanding the formation of the most massive stars. Methods: With this goal in mind we…

Theoretical models and spectroscopic observations of newborn stars suggest that protoplantary disks have an inner "wall" at a distance set by the disk interaction with the star. Around T Tauri stars, the size of this disk hole is expected…

In their earliest stages, protostars accrete mass from their surrounding envelopes through circumstellar disks. Until now, the smallest observed protostar/envelope mass ratio was ~2.1. The protostar L1527 IRS is thought to be in the…

The rarity of young massive stars combined with the fact that they are often deeply embedded has limited the understanding of their formation. Ground based mid-infrared (IR) interferometry is one way of securing the spatial resolution…

We present a 4.5-4.85 micron R=5000 spectrum of the low mass class I young stellar object GSS 30 IRS1 (L=25L_sun) in the rho Ophiuchus core, observed with the infrared spectrometer (ISAAC) on the Very Large Telescope (VLT-UT1). Strong line…

Two decades ago "transitional disks" described spectral energy distributions (SEDs) of T Tauri stars with small near-IR excesses, but significant mid- and far-IR excesses. Many inferred this indicated dust-free holes in disks, possibly…