The nearest known → classical T Tauri star,
situated some 56 → parsecs away in the
constellation → Hydra, far from
any → molecular cloud (abbreviated TW Hya).
It is a variable star with large Hα-emission
→ equivalent width.
TW Hya is similar in mass to the Sun, but is only about
8 million years old. The star appears to be → accreting from a
remarkable → face-on→ protoplanetary disk of dust and gas,
resolved in images from the → Hubble Space Telescope.
Stellar light scattered from the optically thick dust disk is seen from 20 to 230 AU.
The → scattering profile indicates that the disk is
→ flared, not geometrically flat.
TW Hya is accompanied by a group of other low-mass stars with similar ages and
space motions, comprising the → TW Hydrae association.
An → exoplanet of mass nearly 10
→ Jupiters
has been detected around TW Hya. It orbits the star with a period of 3.56 days at 0.04 AU,
inside the inner rim of the disk.
See also: → Hydra.
