Features of the Wind of the Unique Herbig Ae Star HD 190073

Abstract

Results of our spectral monitoring of the Herbig Ae star HD190073 during 2009-2017 at the Crimean Astrophysical Observatory are presented. Over this time, 116 spectra were obtained in the region of the Hα line and 61 in the region of the HeI and NaI D lines. It was found that the parameters of the circumstellar lines are variable and at least three separate components of the variability can be identified: (a) night to night, (b) interseasonal (τ tens of days), (c) slow (τ years). We assume that the interseasonal variability may be related to modulation of the rotational profiles of the star with a period of about 40 days, while the slow variations may be influenced by a hypothetical binarity of the object, direct signs of which have not yet been been discovered. We confirm that the complicated multicomponent structure of the blue absorption components of the Ca II doublet absorption lines, which have already been discussed for several decades, is also observed in the Hα and NaI D2 lines. These features of these lines are presumably related to the existence of a magnetic field with a complicated configuration in this object. The characteristics of this configuration remain unknown and should be the subject of future investigations. We also assume that the sudden changes in the parameters of the lines after JD2455700 may be related to a transformation in the magnetic field of HD190073 predicted previously in the literature. We believe that further studies of this object should include: (a) repeated direct spectropolarimetric measurements of the magnetic field, (b) a search for cyclicity in measurements of the parameters of the profiles of its lines on a time scale of tens of days (owing to rotational modulation) to several years (traces of the presence of a second component), and (c) a study of the variability of other circumstellar lines formed in the wind (e.g., the FeII (42) triplet line).