Disk Accretion in the 10 M[CLC]yr[/CLC] Old T Tauri Stars TW Hydrae and Hen 3-600A
Open Access
- 20 May 2000
- journal article
- research article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 535 (1), L47-L50
- https://doi.org/10.1086/312691
Abstract
We have found that two members of the TW Hydrae association, TW Hydrae and Hen 3-600A, are still actively accreting, based on the ballistic infall signature of their broad Hα emission profiles. We present the first quantitative analysis of accretion in these objects and conclude that the same accretion mechanisms which operate in the well-studied 1 Myr old T Tauri stars can and do occur in older (10 Myr) stars. We derive the first estimates of the disk mass accretion rate in TW Hya and Hen 3-600A, which are 1-2 orders of magnitude lower than the average rates in 1 Myr old objects. The decrease in accretion rates over 10 Myr, as well as the low fraction of TW Hya association objects still accreting, points to significant disk evolution, possibly linked to planet formation. Given the multiplicity of the Hen 3-600 system and the large UV excess of TW Hya, our results show that accretion disks can be surprisingly long lived in spite of the presence of companions and significant UV ionizing flux.Keywords
This publication has 22 references indexed in Scilit:
- A Disk Census for the Nearest Group of Young Stars: Mid-Infrared Observations of the TW Hydrae AssociationThe Astrophysical Journal, 1999
- Mid-Infrared Imaging of the Young Binary Star Hen 3-600: Evidence for a Dust Disk around the PrimaryThe Astrophysical Journal, 1999
- The Structure and Emission of the Accretion Shock in T Tauri StarsThe Astrophysical Journal, 1998
- Accretion and the Evolution of T Tauri DisksThe Astrophysical Journal, 1998
- Disk Accretion Rates for T Tauri StarsThe Astrophysical Journal, 1998
- Spectroscopic evidence for magnetospheric accretion in classical T Tauri starsThe Astronomical Journal, 1994
- Dynamics of binary-disk interaction. 1: Resonances and disk gap sizesThe Astrophysical Journal, 1994
- A search for T Tauri stars based on the IRAS point source catalog.The Astronomical Journal, 1992
- How to unveil a T Tauri starThe Astrophysical Journal Supplement Series, 1989
- Discovery of new isolated T Tauri starsThe Astrophysical Journal, 1989