  Context. RW Aur A is a classical T Tauri star (CTTS) with an unusually rich
emission line spectrum. In 2014 the star faded by ~ 3 magnitudes in the V band
and went into a long-lasting minimum. In 2010 the star suffered from a similar
fading, although less deep. These events in RW Aur A are very unusual among the
CTTS, and have been attributed to occultations by passing dust clouds. Aims. We
want to find out if any spectral changes took place after the last fading of RW
Aur A with the intention to gather more information on the occulting body and
the cause of the phenomenon. Methods. We collected spectra of the two
components of RW Aur. Photometry was made before and during the minimum.
Results. The overall spectral signatures reflecting emission from accretion
flows from disk to star did not change after the fading. However, blue-shifted
absorption components related to the stellar wind had increased in strength in
certain resonance lines, and the profiles and strengths, but not fluxes, of
forbidden lines had become drastically different. Conclusions. The extinction
through the obscuring cloud is grey indicating the presence of large dust
grains. At the same time, there are no traces of related absorbing gas. The
cloud occults the star and the interior part of the stellar wind, but not the
wind/jet further out. The dimming in 2014 was not accompanied by changes in the
accretion flows at the stellar surface. There is evidence that the structure
and velocity pattern of the stellar wind did change significantly. The dimmings
could be related to passing condensations in a tidally disrupted disk, as
proposed earlier, but we also speculate that large dust grains have been
stirred up from the inclined disk into the line-of-sight through the
interaction with an enhanced wind.
