Related papers: A Bayesian Approach to Inferring Accretion Signatu…
Observed Young Stellar Objects (YSOs) are used to study star formation and characterize star forming regions. For this purpose, YSO candidate catalogs are compiled from various surveys, especially in the infrared (IR), and simple selection…
(abridged) Star formation in the outer Galaxy, i.e., outside of the Solar circle, has been lightly studied in part due to low CO brightness of molecular clouds linked with the negative metallicity gradient. Recent infrared surveys provide…
As part of the POISSON project (Protostellar Optical-Infrared Spectral Survey on NTT), we present the results of the analysis of low-resolution NIR spectra 0.9-2.4 um) of two samples of YSOs in Lupus and Serpens (52 and 17 objects), with…
The evolution of young stars and disks is driven by the interplay of several processes, notably accretion and ejection of material. Critical to correctly describe the conditions of planet formation, these processes are best probed…
Very low-mass Class I protostars have been investigated very little thus far. Variability of these young stellar objects (YSOs) and whether or not they are capable of strong episodic accretion is also left relatively unstudied. We…
Formation of massive stars by accretion requires a high accretion rate of > 10^-4 M_sun/yr to overcome the radiation pressure barrier of the forming stars. Here, we study evolution of protostars accreting at such high rates, by solving the…
The results of an optical spectroscopic survey of a sample of young stellar objects (YSOs) and pre-main sequence (PMS) stars in the Lupus Clouds are presented. 92 objects were observed with VLT/FLAMES. All of those objects show IR excess as…
Measured properties of young stellar objects (YSOs) are key tools for research into pre-main-sequence stellar evolution. YSO properties are commonly measured by comparing observed radiation to existing grids of template YSO spectral energy…
This study utilized LAMOST low-resolution spectra to identify M-type YSOs and characterize their accretion signatures. We measured characteristic features, including hydrogen Balmer, Li {\sc i}, He~{\sc i}, Na {\sc i}, and Ca {\sc ii}…
We discuss the importance of accretion in calculating disk models for young stellar objects. In particular, we show that a disk inner rim, irradiated by both the star and the accretion shocks at the stellar surface, can naturally explain…
The PDS 70 system has been subject to many studies in the past year following the discovery of two accreting planets in the gap of its circumstellar disk. Nevertheless, the mass accretion rate onto the star is still not well known. Here we…
Variability is a defining characteristic of young low-mass stars that are still accreting material from their primordial protoplanetary disk. Here we present the largest \textit{HST} variability study of Classical T Tauri stars (CTTS) to…
Variability in the brightness of Young Stellar Objects (YSOs) is a common phenomenon that can be caused by changes in various factors, including accretion, extinction, disk morphology, interactions between the disk and the stellar…
FU Ori type objects (FUors) are decades-long outbursts of accretion onto young stars that are strong enough to viscously heat disks so that the disk outshines the central star. We construct models for FUor objects by calculating emission…
Evidence abounds that young stellar objects undergo luminous bursts of intense accretion that are short compared to the time it takes to form a star. It remains unclear how much these events contribute to the main-sequence masses of the…
Photometric variability in young stellar objects (YSOs) provides critical insight into the mechanisms of mass accretion, disk evolution, and circumstellar extinction in early stellar evolution. We present an analysis of day-timescale…
A homogeneous determination of basic stellar parameters of young stellar object (YSO) candidates is needed to confirm their evolutionary stage, membership to star forming regions (SFRs), and to get reliable values of the quantities related…
We present the analysis of 34 new VLT/X-Shooter spectra of young stellar objects in the Chamaeleon I star forming region, together with four more spectra of stars in Taurus and two in Chamaeleon II. The broad wavelength coverage and…
Interpreting the short-timescale variability of the accreting, young, low-mass stars known as Classical T Tauri stars remains an open task. Month-long, continuous light curves from the Transiting Exoplanet Survey Satellite (\textit{TESS})…
The dependence of the mass accretion rate on the stellar properties is a key constraint for star formation and disk evolution studies. Here we present a study of a sample of stars in the Chamaeleon I star forming region carried out using…