Accretion variability in Young Stellar Objects: results from the Gaia Photometric Science Alerts
- Author(s)
- Zsofia Nagy, Péter Àbrahám, Ágnes Kóspál, Fernando Cruz-Sáenz de Miera, Eleonora Fiorellino, Teresa Giannini, Michael Kuhn, Mária Kun, Gabor Marton, Patrik Németh, Sunkyung Park, Michal Siwak, László Szabados, Zsófia Marianna Szabó, Máté Szilágyi
- Abstract
Young stellar objects (YSOs) are accreting material from their disc via magnetic field lines. About half of YSOs show photometric variations on daily-weekly timescales, with an amplitude of a few times 0.1 mag. Some young stars show brightness variations on even longer time-scales: months, years, centuries. These variations are related to different physical processes, such as changes in circumstellar extinction or the accretion rate. Eruptive young stars show brightness variations with an amplitude of a few magnitudes and remain bright on longer timescales. These outbursts of eruptive YSOs are caused by a sudden increase of the mass accretion rate by a few orders of magnitude. Eruptive YSOs are commonly divided into two main classes: EX Lupi-type stars (EXors) and FU Orionis-type stars (FUors). The former show brightenings of 2-4 mag, last for less than a year and are recurrent, the latter brighten by up to 5 magnitudes and last for several decades. So far the number of confirmed FUors is limited to no more than a dozen while the number of known EXors is limited to less than 25, including candidates. The Gaia Photometric Science Alerts System with its large sky coverage and approximately monthly cadence, provides a highly efficient tool to identify new eruptive YSOs. The literature contains several young eruptive stars discovered by Gaia, namely the FUor Gaia17bpi (Hillenbrand et al., 2018), Gaia19ajj (Hillenbrand etal. 2019), and Gaia19bey (Hodapp et al. 2020). Our group has recently published the discovery of two new FUors, Gaia18dvy (Szegedi-Elek et al. 2020) and Gaia21elv (Nagy et al. 2023), three new EXors, Gaia20eae (Cruz-Saenz de Miera et al. 2022), Gaia19fct (Park et al. 2022), and Gaia23bab (Giannini et al., submitted), and other eruptive YSOs which cannot be classified as EXors or FUors, such as Gaia21bty (Siwak et al. 2023) and Gaia18cjb (Fiorellino et al., submitted). We are currently analyzing the follow-up photometry and spectroscopy of several Gaia alerted young eruptive star candidates. Our follow-up observations include photometry using 1-m class telescopes in Hungary and Poland, and spectroscopy using telescopes such as the TNG, the NOT, the NTT, the GTC, the LBT, the VLT, and the IRTF. I will present results on follow-up observations of eruptive YSOs found from Gaia alerts.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- HUN-REN Hungarian Research Network, Eötvös Loránd University Budapest, Max-Planck-Institut für Astronomie, Eötvös Loránd Research Network, University of Toulouse, INAF Astronomical Observatory of Capodimonte , INAF - Osservatorio Astronomico di Roma, University of Hertfordshire, Max-Planck-Institut für Radioastronomie, University of St. Andrews
- Publication date
- 07-2024
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/33ac9650-2009-44a4-bc5a-81abb480fec9