Recurrent strong outbursts of an EXor-like young eruptive star Gaia20eae

TL;DR

This paper reports on Gaia20eae, a young eruptive star exhibiting recurrent outbursts, with detailed photometric and spectroscopic analysis confirming its classification as an EXor-type variable star.

Contribution

The study provides the first detailed observational characterization of Gaia20eae, confirming it as a new EXor-type eruptive young star with measured accretion rates and spectral features.

Findings

Gaia20eae experienced multiple outbursts with ~3 mag brightness increase.

Spectroscopic data show evolving accretion rates and wind features.

Estimated accretion rate during dimming phase is 3-8 x 10^{-7} M_sun/yr.

Abstract

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 showed the shape of a typical eruptive young star. We carried out observations to confirm Gaia20eae as an eruptive young star and classify it. Its pre-outburst spectral energy distribution shows that Gaia20eae is a moderately embedded Class II object with $L_\mathrm{bol} = 7.22$ L$_\odot$. The color-color and color-magnitude diagrams indicate that the evolution in the light curve is mostly gray. Multiple epochs of the H$\alpha$ line profile suggest an evolution of the accretion rate and winds. The near-infrared spectra display several emission lines, a feature typical of EXor-type eruptive young stars. We estimated the mass accretion rate during the dimming phase to be $\dot{M} = 3-8 \times 10^{-7}$ M$_\odot$ yr$^{-1}$, higher than typical T Tauri stars of similar mass and comparable to other EXors. We conclude Gaia20eae is a new EXor-type candidate.