Related papers: Quantitative Spectroscopic Diagnostics for FU Orio…

The evolution of young stars and planet-forming environments is intrinsically linked to their nascent surroundings. This is particularly evident for FU Orionis (FUor) objects$-$a class of young protostars known for dramatic outbursts…

Eruptive accretion events are expected to play an important role in the mass buildup stage of individual star formation. FU Ori objects (FUors) experience the most extreme eruptive outbursts, which raise the accretion rate of the disk from…

FUor outbursts in young stellar objects (YSOs) are the most dramatic events among episodic accretion phenomena. The origin of these bursts is not clear: disk instabilities and/or disk perturbations by an external body being the most viable…

Eruptive stars are a class of young stellar objects that show an abrupt increase in their luminosity. These burst-like episodes are thought to dominate the stellar accretion process during the class 0/class I stage. We present an overview…

FU Orionis-type objects are young, low-mass stars with large outbursts in visible light that last for several years or decades. They are thought to represent an evolutionary phase during the life of every young star when accretion from the…

We present mid-infrared Spitzer-IRS spectra of the well-known UX Orionis star VV Ser. We combine the Spitzer data with interferometric and spectroscopic data from the literature covering UV to submillimeter wavelengths. The full set of data…

Optical and infrared surveys have detected increasing numbers of disc accretion outbursts in young stars. Some models of these FU Ori-type events predict that the outburst should start at near- to mid-infrared wavelengths before an optical…

During the pre-main-sequence (pre-MS) evolution stage of a star, significant amounts of stellar mass are accreted during episodic accretion events, such as multi-decade FUor-type outbursts. Here, we present a near-infrared spectroscopic…

The accretion luminosity of an FU Ori disk is a fundamental system parameter, but a challenging one to estimate for all but the most well-studied systems. FU Ori objects are dynamically evolving accretion disks, especially close in time to…

We present 5-35 $\mu$m spectra, taken with the Infrared Spectrograph (IRS) on the Spitzer Space Telescope, of five FU Orionis objects: FU Ori, V1515 Cyg, V1057 Cyg, BBW 76, and V346 Nor. All but V346 Nor reveal amorphous silicate grains in…

We present the first high spatial resolution near-infrared direct and polarimetric observations of Parsamian 21, obtained with the VLT/NACO instrument. We complemented these measurements with archival infrared observations, such as…

FU Orionis are young stellar objects undergoing episodes of enhanced luminosity, which are generally ascribed to a sudden increase of mass accretion rate in the surrounding protostellar disc. Models invoking a thermal instability in the…

Context. Gaia18cjb is one of the Gaia-alerted eruptive young star candidates which has been experiencing a slow and strong brightening during the last 13 years, similar to some FU Orionis-type objects. Aims. The aim of this work is to…

Context. Although many studies have been performed so far, there are still dozens of low-mass stars and brown dwarfs in the young sigma Orionis open cluster without detailed spectroscopic characterisation. Aims. We look for unknown strong…

We show that if FU Orionis objects harbour hot Jupiters embedded in their discs, the resulting non-axisymmetric dissipation profile in the disc would be manifest as time-dependent distortions in the absorption line profiles of these…

We present the first results from a 124 night J, H, K near-infrared monitoring campaign of the dark cloud L 1003 in Cygnus OB7, an active star-forming region. Using 3 seasons of UKIRT observations spanning 1.5 years, we obtained…

We present Keck Interferometer observations of the three prototypical FU Orionis stars, FU Ori, V1057 Cyg, and V1515 Cyg. With a spatial resolution of a few milli-arcseconds and a spectral resolution of 2000, our near-infrared observations…

We present the results of high-resolution (R $\ge$ 30,000) optical and near-infrared spectroscopic monitoring observations of a FU Orionis-type object, V960 Mon, which underwent an outburst in 2014 November. We have monitored this object…

This paper discusses evidence for and properties of disks associated to brown dwarfs in the star-forming region rho-Oph. We selected nine objects fr om the ISOCAM survey of Bontemps et al. (2001) that have detections in the two mid-infrared…

Aims: The objective of this study is to determine the general X-ray properties of the young stars in the external regions of the sigma Orionis cluster (tau ~ 3 Ma, d ~ 385 pc) and yield constraints on the X-ray emission of brown dwarfs.…