Gaia20bdk – New FU Ori-type star in the Sh 2-301 star-forming region

Le résumé fourni par la source

Context. We analyse multi-colour photometric and spectroscopic observations of the young stellar object (YSO) Gaia20bdk. Aims. We aim to investigate the exact nature of the eruptive phenomenon that the star has been undergoing since 2018. Methods. We used public-domain archival photometry to characterise the quiescent phase and to establish the major physical parameters of the progenitor. We used our own optical and infrared (IR) photometry and spectroscopy, along with data from the public domain, to study the outburst. Results. Gaia20bdk is a member of the Sharpless 2-301 star-forming region, at a distance of 3.3 kpc. The progenitor is a rather massive 2.7 ± 0.5 M⊙, G7-type Class I young star, with an effective temperature of 5300−300+500 K and bolometric luminosity of 11 ± 2 L⊙. The optical and IR photometric and spectroscopic data obtained during the outburst reveal a variety of signatures commonly found in classical FU Ori-type stars (FUors). Our disc modelling gives a bolometric luminosity of 100 − 200 L⊙ and mass accretion rate of 1 − 2 × 10−5 M⊙ yr−1, also confirming the object’s FUor classification. Further monitoring is necessary to track the light changes, accretion rate, and spectral variations, as well as to understand the mechanisms behind the disc flickering.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.