TIME-VARIABLE ACCRETION IN THE TW Hya STAR/DISK SYSTEM

Journal Article · Sun Oct 10 00:00:00 EDT 2010 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/722/1/L28· OSTI ID:21452770

Eisner, J A; McCarthy, D; Kulesa, C; Swift, B J; Teske, J ^[1]; Doppmann, G W

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1. Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States)

We present two epochs of observations of TW Hya from the high-dispersion near-IR spectrograph ARIES at the Multiple Mirror Telescope. We detect strong emission from the Br{gamma} transition of hydrogen, indicating an accretion rate substantially larger than previously estimated, using hydrogen line emission. The Br{gamma} line strength varies across our two observed epochs. We also measure circumstellar-to-stellar flux ratios (i.e., veilings) that appear close to zero in both epochs. These findings suggest that TW Hya experiences episodes of enhanced accretion while the inner disk remains largely devoid of dust. We discuss several physical mechanisms that may explain these observations.

• OSTI ID: 21452770
• Journal Information: Astrophysical Journal Letters, Vol. 722, Issue 1; Other Information: DOI: 10.1088/2041-8205/722/1/L28; ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
DUSTS
EMISSION
HYDROGEN
STARS
TELESCOPES
ELEMENTS
NONMETALS