Title
A Multiwavelength, Multiepoch Monitoring Campaign of Accretion Variability in T Tauri Stars from the ODYSSEUS Survey. III. Optical Spectra
Date Issued
2024
Author(s)
Wendeborn, John
Espaillat, Catherine C.
Thanathibodee, Thanawuth
Robinson, Connor E.
Pittman, Caeley V.
Calvet, Nuria
Muzerolle, James
Walter, Fredrick M.
Eislöffel, Jochen
Manara, Carlo F.
Kóspál, Ágnes
Ábrahám, Péter
Claes, Rik
Campbell-White, Justyn
McGinnis, Pauline
Mauco, Karina
Gameiro, Filipe
Guo, Zhen
DOI
10.3847/1538-4357/ad65ed
10.48550/arXiv.2408.04465
Abstract
Classical T Tauri Stars (CTTSs) are highly variable stars that possess gas- and dust-rich disks from which planets form. Much of their variability is driven by mass accretion from the surrounding disk, a process that is still not entirely understood. A multiepoch optical spectral monitoring campaign of four CTTSs (TW Hya, RU Lup, BP Tau, and GM Aur) was conducted along with contemporaneous Hubble Space Telescope (HST) UV spectra and ground-based photometry in an effort to determine accretion characteristics and gauge variability in this sample. Using an accretion flow model, we find that the magnetospheric truncation radius varies between 2.5 and 5 R <SUB>⋆</SUB> across all of our observations. There is also significant variability in all emission lines studied, particularly Hα, Hβ, and Hγ. Using previously established relationships between line luminosity and accretion, we find that, on average, most lines reproduce accretion rates consistent with accretion shock modeling of HST spectra to within 0.5 dex. Looking at individual contemporaneous observations, however, these relationships are less accurate, suggesting that variability trends differ from the trends of the population and that these empirical relationships should be used with caution in studies of variability. <SUP>*</SUP> Based on observations collected at the European Southern Observatory under ESO program 106.20Z8.
Subjects
Stellar accretion
T Tauri stars
1578
1681
Astrophysics - Solar and Stellar Astrophysics