Non-stationary dynamo and magnetospheric accretion processes of the classical T Tauri star V2129 Oph

摘要: We report here the first results of a multiwavelength campaign focussing on magnetospheric accretion processes classical T Tauri star V2129 Oph. In this paper, we present spectropolarimetric observations collected in 2009 July with ESPaDOnS at Canada–France–Hawaii Telescope and contemporaneous photometry secured SMARTS facility. Circularly polarized Zeeman signatures are clearly detected, both photospheric absorption accretion-powered emission lines, from time-series which reconstruct new maps magnetic field, brightness surface V2129 Oph using our newest tomographic imaging tool – to be compared those derived old 2005 June data set, re-analysed exact same way. We find that July, hosts octupolar dipolar field components about 2.1 0.9 kG, respectively, tilted by 20° respect rotation axis; conclude large-scale topology changed significantly since (when octupole dipole were 1.5 three times weaker, respectively), demonstrating is generated non-stationary dynamo. also show features dark spot localized area emission, close main region (hosting fields up 4 kG July). finally obtain shear half as strong solar. From fluxes estimate observed average logarithmic rate (in M⊙ yr−1) −9.2 ± 0.3 epochs, peaking −9.0 maximum. It implies particular radius truncates inner disc 0.93 0.50 corotation (where Keplerian period equals stellar period) June, respectively.