Bibcode
Martin, E. L.; Magazzu, A.; Rebolo, R.
Bibliographical reference
Astronomy and Astrophysics (ISSN 0004-6361), vol. 257, no. 1, p. 186-198.
Advertised on:
4
1992
Citations
44
Refereed citations
38
Description
We report on intermediate-to-high resolution spectroscopy and standard
broadband photometry of late-type visual companions to early-type stars.
Our program stars are drawn from the sample of post-T-Tauri candidates
studied by Lindroos (1986). Measurement of radial velocities and
derivation of the surface abundances of lithium and heavier elements
(Ca, Fe, Si, and Ti) allow us to identify genuine post-T Tauris (PTTS)
with a high degree of confidence. Only 5 out of the 14 stars studied by
us can be unambiguously classified as premain-sequence objects. On the
Hertzsprung-Russell diagram all five lie closer to the ZAMS than
classical T Tauris do. The PTTS are located on the radiative part of
premain-sequence evolution tracks of stars with mass around 1 solar
mass, overlapping with some stars of the so-called naked T Tauri
population. We discuss the general properties of PTTS, which are similar
to those of NTTS. The metallicity of PTTS is close to solar, as expected
for Population I stars. The abundance of lithium in PTTS with masses
higher than 1 solar mass is found to be cosmic, while in PTTS with
masses 0.9-0.8 solar mass lithium is depleted by about one order of
magnitude.