Related papers: Gaia23bab : a new EXor
Episodic accretion is a fundamental process in the build-up of the stellar mass. EX Lupi-type eruptive young stars (EXors) represent one of the main types of episodic accretion. We study the recently discovered EXor Gaia23bab during its…
We analyzed optical/near-IR Large Binocular Telescope spectra of 16 sources alerted by Gaia between 2021 and 2024 due to significant photometric variability. Half of the spectra were taken during quiescence and the rest during a burst or at…
We present follow-up photometric and spectroscopic observations, and subsequent analysis of Gaia20eae. This source triggered photometric alerts during 2020 after showing a $\sim$3 mag increase in its brightness. Its Gaia Alert light curve…
Gaia21bty, a pre-main sequence star that previously had shown aperiodic dips in its light curve, underwent a considerable $\Delta G\approx2.9$ mag brightening that occurred over a few months between 2020 October - 2021 February. The Gaia…
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…
The light curve of Gaia23bab (= SPICY 97589) shows two significant ($\Delta G>2$ mag) brightening events, one in 2017 and an ongoing event starting in 2022. The source's quiescent spectral energy distribution indicates an embedded ($A_V>5$…
Context. Among known young stellar objects (YSOs), those exhibiting the most dramatic increases in brightness due to sudden increase in mass accretion rate are eruptive young stars. Gaia20dsk is one of the Gaia-alerted young star candidates…
The Gaia Alert System issued an alert on 2020 August 28, on Gaia 20eae when its light curve showed a $\sim$4.25 magnitude outburst. We present multi-wavelength photometric and spectroscopic follow-up observations of this source since 2020…
We report on the source Gaia 17bpi and identify it as a new, ongoing FU Ori type outburst, associated with a young stellar object. The optical lightcurve from Gaia exhibited a 3.5 mag rise with the source appearing to plateau in mid/late…
FU Orionis objects (FUors) are eruptive young stars, which exhibit outbursts that last from decades to a century. Due to the duration of their outbursts, and to the fact that only about two dozens of such sources are known, information on…
Gaia21bja is a Gaia alerted young stellar object (YSO) that exhibits at least seven quasi-peridoic brightenings over a 20 year-long light curve with durations of 1.5-2 years and amplitudes up to $\sim$1.7 mag in the Gaia $G$-band. We…
Young stars show variability on different time-scales from hours to decades, with a range of amplitudes. We studied two young stars, which triggered the Gaia Science Alerts system due to brightenings on a time-scale of a year. Gaia20bwa…
We report photometry and spectroscopy of the outburst of the young stellar object Gaia19bey. We have established the outburst light curve with archival Gaia G, ATLAS Orange, ZTF r-band and Pan-STARRS rizy-filter photometry, showing an…
Stellar outbursts from variable or periodic accretion are thought to be ubiquitous across young stellar populations. However, relatively few outbursting objects have been discovered to date. Here, we present the characterisation of a new…
We present an optical/near-IR survey of 11 variable young stars (EXors and EXor candidates) aimed at deriving and monitoring their accretion properties. About 30 optical and near-infrared spectra ($\Re$ $\sim$ 1500-2000) were collected…
Accretion-driven outbursts in young stellar objects remain poorly understood, largely limited by a statistically small sample of closely followed-up events. This underscores the importance of a thorough exploration of each outbursting…
Gaia19fct is one of the Gaia-alerted eruptive young stars that has undergone several brightening events. We conducted monitoring observations using multi-filter optical and near-infrared photometry, as well as near-infrared spectroscopy, to…
V1741 Sgr (= SPICY 71482/Gaia22dtk) is a Classical T Tauri star on the outskirts of the Lagoon Nebula. After at least a decade of stability, in mid-2022, the optical source brightened by ~3 mag over two months, remained bright until early…
Context. We analyse multi-colour photometric and spectroscopic observations of a Young Stellar Object Gaia20bdk. Aims. We aim to investigate the exact nature of the eruptive phenomenon that the star has been experiencing since 2018.…
Outbursts due to dramatic increases in the mass accretion rate are the most extreme type of variability in young stellar objects. We searched for outbursts among 319 protostars in the Orion molecular clouds by comparing 3.6, 4.5, and 24…