1998A&A...338..674W

We present high spectral resolution observations of the absorption lines of CaII and NaI associated with the circumstellar gas disk surrounding the two A-type shell stars HR 10 and HD 85905. Data taken over two four-night periods in January and November 1997 reveal substantial changes in the circumstellar absorption line profiles between successive observations of both stars. Such variable features have both blue and red-shifted velocities up to 50km/s away from the central absorbing component, and are similar to those routinely observed in the β Pictoris system. The sporadic presence of the circumstellar absorption components observed towards both HR 10 and HD 85905 may be explained by the infalling evaporating comet model developed for the β Pictoris system by Beust et al. (1990A&A...236..202B) We note that variable circumstellar absorption features have also been detected in rapidly rotating A-type stars, such that they may be suffering irregular mass-loss that could give rise to similar circumstellar disks and shells.