Periodic variability in the emission spectrum of T Tauri

Abstract

Listen

Translate article

<i>Context. <i/>Long timescale periodic variations in T Tauri stars may be related to changes in their protoplanetary disks.<i>Aims. <i/>A lengthy homogeneous series of spectral observations of the CTTS T TauN has been analyzed. <i>Methods. <i/>We search for periodicity in the equivalent widths of the emission lines in the optical and in the UV.<i>Results. <i/>Significant periodic variation is found in the equivalent widths of H<i>β<i/> and CaII emission features on a time scale of 33 <i>±<i/> 1.5 days. Variations in the UV emission lines based on archival IUE spectra are also consistent with this period.<i>Conclusions. <i/>This is clearly not the rotation period of the star, which is known to be 2.8 days, and must arise somewhere in the magnetosphere, disk or outflow region.