31 research outputs found
Episodic formation of cometary material in the outburst of a solar-like young star
Our Solar System originated in interstellar gas and dust; the latter is in
the form of amorphous silicate particles and carbonaceous dust. The composition
of cometary material shows that a significant fraction of the amorphous
silicates was transformed into crystalline form during the early evolution of
the protosolar nebula. How and when this transformation happened has been
controversial, with the main options being heating by the young Sun or shock
heating. Here we report mid-infrared features in the outburst spectrum of the
young solar-like star EX Lupi that were not present in quiescence. We attribute
them to crystalline forsterite; the crystals were produced via thermal
annealing in the surface layer of the inner disk by heat from the outburst, a
process that has hitherto not been considered. The observed lack of cold
crystals excludes shock heating at larger radii.Comment: 13 pages of PDF, including Supplementary Informatio