Having disk-to-star accretion rates on the order of 10 ^ { -4 } M _ { \odot } /yr , FU Orionis-type stars ( FUors ) are thought to be the visible examples for episodic accretion .
FUors are often surrounded by massive envelopes , which replenish the disk material and enable the disk to produce accretion outbursts .
We observed the FUor-type star V346 Nor with ALMA at 1.3 mm continuum and in different CO rotational lines .
We mapped the density and velocity structure of its envelope and analyzed the results using channel maps , position-velocity diagrams , and spectro-astrometric methods .
We discovered a pseudo-disk and a Keplerian disk around a 0.1 M _ { \odot } central star .
We determined an infall rate from the envelope onto the disk of 6 \times 10 ^ { -6 } M _ { \odot } /yr , a factor of few higher than the quiescent accretion rate from the disk onto the star .
This hints for a mismatch between the infall and accretion rates as the cause of the eruption .