The dimming events of the CTTS RW Aur A (poster)

The study of the inner gaseous disc of YSOs is crucial to understand the physical processes ruling disc evolution and its connection with planet formation. In this poster, I will present our results on the inner disc properties of the CTTS RW AurA. The RW Aur system has captured the attention of astronomers for its dimming events. By using X-SHOOTER spectra in the bright and dim states, we compare the NIR CO emission in order to shed light on this mystery. In general, the CO emission traces a warm (T=2000-5000K) and dense (NCO>1e12cm-2) gas as expected in the innermost region of discs. Both states need a cool (T=3000K) and dense (NCO=1e21cm-2) gas to reproduce the observations, with the emitting region located just inside the dust sublimation radius. By comparing the SED (from ~300 to ~1000 nm) and the CO emission of both states, we find that the dimming can be due to absorption by a layer of large grains with optical depth slowly declining from 2.8 to 1.6. The accretion rate remains constant (Macc~2e-8 Mo/yr) if one assumes that the same layer of dust also occults the accretion line emitting region. This excludes accretion bursts as the main cause of RWAurA brightness variability.