We report the discovery of five T Tauri star systems, two of which are resolved binaries, in the vicinity of the nearest known region of recent star formation: the TW Hydrae Association. The newly discovered systems display the same signatures of youth (namely high X-ray flux, large Li abundance, and strong chromospheric activity) and the same proper motion as the original five members. These similarities firmly establish the group as a bona fide T Tauri association, unique in its proximity to Earth and its complete isolation from any known molecular clouds. At an age of ∼10 Myr and a distance of ∼50 pc, the association members are excellent candidates for future studies of circumstellar disk dissipation and the formation of brown dwarfs and planets. Indeed, as an example, our speckle imaging revealed a faint, very likely companion 2″ north of CD -33° 7795 (TWA 5). Its color and brightness suggest a spectral type of ∼M8.5 which, at an age of ∼107 yr, implies a mass ∼20MJup.
- Open clusters and associations: Individual (TW Hydrae)
- Stars: Low-mass, brown dwarfs
- Stars: Pre-main-sequence
- X-rays: Stars
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science