Nearby young stars
Astronomy & Astrophysics, Main Journal
(accepted)
R. Wichmann [1], J.H.M.M. Schmitt [1], S. Hubrig [2]
- Hamburger Sternwarte, Gojenbergsweg 112,
D-21029 Hamburg, Germany
- European Southern Observatory, Karl-Schwarzschild-Str. 2,
D-85748 Garching bei München, Germany
Abstract
We present the results of an extensive all-sky survey of nearby stars
of spectral type F8 or later in a systematic search of
young (zero-age main sequence) objects.
Our sample has been derived by cross-correlating the ROSAT All-Sky
Survey and the TYCHO catalog, yielding a total of 754 candidates
distributed more or less randomly over the sky.
Follow-up spectroscopy of these candidate objects has been
performed on 748 of them.
We have discovered a tight kinematic group of ten stars
with extremely
high lithium equivalent widths that are presumably younger than
the Pleiades, but again distributed rather uniformly over the sky.
Furthermore, about 43 per cent of our candidates have
detectable levels of lithium, thus indicating that these are relatively
young objects with ages not significantly above the Pleiades age.
Key words:
Surveys - solar neighbourhood - Stars: kinematics -
Stars: late-type
Contact: Rainer Wichmann.
Preprint:
(gzipped PS, 192 KB),
(PDF, 506 KB)