Results 21 to 30 of about 206 (176)

Measuring the Magnetic Field on the Classical T Tauri Star BP Tauri [PDF]

The Astrophysical Journal, 1999
We examine several theories that describe how stellar magnetic fields on classical T Tauri stars (CTTSs) interact with their surrounding accretion disks. We demonstrate that these theories require magnetic field strengths ranging from a few hundred to several thousand gauss, depending on which model is used and more importantly on the properties of ...
Christopher M. Johns‐Krull, Jeff A. Valenti, Christopher Koresko   +2 more
openaire   +1 more source

The Spectral Variability of the Classical T Tauri Star DR Tauri

The Astronomical Journal, 2001
We present the analysis of 103 spectra, collected over more than a decade, of the classical T Tauri star DR Tau observed with the Hamilton echelle spectrograph at Lick Observatory. The star exhibits strong emission lines that show substantial variety and variability in their profile shapes. The emission lines show signatures of both outflow and infall,
Silvia H. P. Alencar, Christopher M. Johns-Krull, Gibor Basri   +2 more
openaire   +1 more source

A Hot Wind from the Classical T Tauri Stars: TW Hydrae and T Tauri [PDF]

The Astrophysical Journal, 2005
Spectroscopy of the infrared He I (10830A) line with KECK/NIRSPEC and IRTF/CSHELL, and of the ultraviolet C III (977A) and O VI (1032A) emission with FUSE reveals that the classical T Tauri star TW Hydrae exhibits P Cygni profiles, line asymmetries, and absorption indicative of a continuous, fast (~400 km/s), hot (~300,000 K) accelerating outflow with ...
Dupree, A. K., Brickhouse, N. S., Smith, Graeme H., Strader, Jay   +3 more
openaire   +2 more sources

A Jet Associated with the Classical T Tauri Star RY Tauri

The Astrophysical Journal, 2008
High spatial resolution images have been taken on the Gemini North telescope of the classical T Tauri star RY Tauri. The Hα image, with the continuum properly subtracted, shows a jet extending out to at least 31'' at a position angle of about 295° from the star. A counterjet extending to at least 3.5' in the opposite direction is also visible.
Gilbert St‐Onge, Pierre Bastien
openaire   +1 more source

HIGH-RESOLUTION ULTRAVIOLET RADIATION FIELDS OF CLASSICAL T TAURI STARS* [PDF]

The Astrophysical Journal, 2014
ABSTRACT The far-ultraviolet (FUV; 912–1700 Å) radiation field from accreting central stars in classical T Tauri systems influences the disk chemistry during the period of giant planet formation. The FUV field may also play a critical role in determining the evolution of the inner disk (r < 10 AU), from a gas- and dust-rich primordial
France, Kevin, Schindhelm, Eric, Bergin, Edwin, Roueff, Evelyne, Paris, Hervé   +4 more
openaire   +4 more sources

Mid‐infrared Spectroscopy of Disks around Classical T Tauri Stars [PDF]

The Astrophysical Journal Supplement Series, 2004
AASTEX, 10 pages text, 2 figures, 1 table, published September 2004 in The Astrophysical Journal Supplement ...
Forrest, W. J., Sargent, B., Furlan, E., D'Alessio, P., Calvet, N., Hartmann, L., Uchida, K. I., Green, J. D., Watson, D. M., Chen, C. H., Kemper, F., Keller, L. D., Sloan, G. C., Herter, T. L., Brandl, B. R., Houck, J. R., Barry, D. J., Hall, P., Morris, P. W., Najita, J., Myers, P. C.   +20 more
openaire   +3 more sources

Magnetospherically Mediated Accretion in Classical T Tauri Stars [PDF]

Symposium - International Astronomical Union, 1997
Observational evidence suggests that disk accretion in low mass stars is mediated by the stellar magnetosphere in the inner few stellar radii of a star/accretion disk system. A strong stellar field appears to disrupt the inner disk and channel accreting material in a funnel flow toward the stellar surface.
openaire   +2 more sources

Pre-main-sequence Brackett Emitters in the APOGEE DR17 Catalog: Line Strengths and Physical Properties of Accretion Columns

The Astrophysical Journal, 2022
Very young ( t ≲ 10 Myr) stars possess strong magnetic fields that channel ionized gas from the interiors of their circumstellar disks to the surface of the star.
Hunter Campbell, Elliott Khilfeh, Kevin R. Covey, Marina Kounkel, Richard Ballantyne, Sabrina Corey, Carlos G. Román-Zúñiga, Jesús Hernández, Ezequiel Manzo Martínez, Karla Peña Ramírez, Alexandre Roman-Lopes, Keivan G. Stassun, Guy S. Stringfellow, Jura Borissova, S. Drew Chojnowski, Valeria Ramírez-Preciado, Jinyoung Serena Kim, Javier Serna, Amelia M. Stutz, Ricardo López-Valdivia, Genaro Suárez, Jason E. Ybarra, Penélope Longa-Peña, José G. Fernández-Trincado   +23 more
doaj   +1 more source

Oscillations of the Boundary Layer and High-frequency QPOs

EPJ Web of Conferences, 2014
We observed persistent high-frequency oscillations of the boundary layer near an accreting, weakly-magnetized star in global 3D MHD simulations. The tilted dipole magnetic field is not strong enough to open a gap between the star and the disk.
Blinova A. A., Bachetti M., Romanova M. M.   +2 more
doaj   +1 more source

Spectropolarimetry of the Classical T Tauri Star TW Hydrae [PDF]

The Astronomical Journal, 2006
We present high resolution (R ~ 60,000) circular spectropolarimetry of the classical T Tauri star TW Hydrae. We analyze 12 photospheric absorption lines and measure the net longitudinal magnetic field for 6 consecutive nights. While no net polarization is detected the first five nights, a significant photospheric field of Bz = 149 \pm 33 G is found on ...
Yang, H., Johns-Krull, C. M., Valenti, J. A.   +2 more
openaire   +2 more sources