Abstract:
The Gaia Alert System issued an alert on 2020 August 28, on Gaia 20eae when its light curve showed a ∼4.25
magnitude outburst. We present multiwavelength photometric and spectroscopic follow-up observations of this
source since 2020 August and identify it as the newest member of the FUor/EXor family of sources. We find that
the present brightening of Gaia 20eae is not due to the dust-clearing event but due to an intrinsic change in the
spectral energy distribution. The light curve of Gaia 20eae shows a transition stage during which most of its
brightness (∼3.4 mag) has occurred on a short timescale of 34 days with a rise rate of 3 mag/month. Gaia 20eae
has now started to decay at a rate of 0.3 mag/month. We have detected a strong P Cygni profile in Hα, which
indicates the presence of winds originating from regions close to the accretion. We find signatures of very strong
and turbulent outflow and accretion in Gaia 20eae during this outburst phase. We have also detected a redshifted
absorption component in all of the Ca II IR triplet lines consistent with a signature of hot infalling gas in the
magnetospheric accretion funnel. This enables us to constrain the viewing angle with respect to the accretion
funnel. Our investigation of Gaia 20eae points toward magnetospheric accretion being the phenomenon for the
current outburst.
