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Context. Emission and absorption line profiles which are formed in theinteraction of pre-main sequence (PMS) stars and their circumstellarenvironment are found to be variable at various timescales. Aims. Weinvestigate the patterns and timescales of temporal line profile variability inorder to explore the dynamical circumstellar environment of the PMS Herbig Aestar V351 Ori. Methods.We obtained 45 high-resolution (R~28,000) spectra ofV351 Ori at timescales of hours, days, and months.We analysed the H\alpha lineprofiles and also examined the H\beta, NaD1 and NaD2 line profiles to explorethe nature of the spectroscopic variability. Results. The H\alpha line profilesshowed strong variations over all timescales. The shape of the profiles changedover timescales of a day. Single as well as simultaneous event(s) ofblue-shifted and red-shifted transient absorption components (TACs), i.e.signatures of outflow and infall, were also observed in the H\alpha lineprofiles. The shortest period of variation in the TACs was < 1 hour. Alltransient absorption events were found to decelerate with a rate of a few tofractions of m s-2. The depth and width of the TACs were also changing withtime. The presence of elongated red-shifted components at some epochs supportsthe episodic nature of accretion. Conclusions. Variable emission and absorptioncomponents detected in H\alpha line profiles show the dynamic nature ofinteraction between V351 Ori and its circumstellar environment. The H\alphanon-photospheric profiles of the star most probably originate in the disk wind.Episodic accretion of gaseous material at a slow rate and outflow of clumpygaseous material are still occurring in V351 Ori at an age of ~6.5 Myr. Dynamicmagnetospheric accretion and disk wind emerge as the most satisfactory modelfor interpreting the observed line profile variations of V351 Ori.

Variable circumstellar activity of V351 Orionis