Outbursts of young Sun-like stars may change how terrestrial planets form

While the Sun is nowadays a quiet and well-balanced star, in its first few million years it might have been often out of temper, like thos young low-mass stars which episodically undergo unpredictable outbursts The prototype of one of the two classes of young erupting stars, E Lupi, had its historically largest outburst in 2008. It brightened by factor of 30 for six months, due to elevated accretion from th circumstellar disk on to the star. Our group observed the system durin the outburst, and discovered the crystallisation of amorphous silicat grains in the inner disk by the heat of the outburst. Our mid-infrare monitoring of the freshly produced crystals revealed that their emissio in the inner disk quickly dropped already within a year after th outburst. Here we report on new observations of the 10 µm silicat feature, obtained with the MIDI and VISIR instruments at Parana Observatory, which demonstrate that within five years practically al forsterite disappeared from the inner disk. We attempt to model thi process by an expanding wind that transports the crystals from th terrestrial zone to outer disk regions where comets are supposed t form. Since the eruptions of EX Lup are recurrent, we speculate that th early Sun also experienced similar brightenings, and the formin planetary system might have incorporated some of the mineralogical an chemical yields provided by the outbursts. EX Lup, as a proxy for th proto-Sun, may be a telltale object to understand the origin o molecules and minerals we routinely encounter on Eart