Summary: Mon. Not. R. Astron. Soc. 000, 000--000 (0000) Printed 20 August 1996 (MN L A T E X style file v1.3)
Lithium abundance in field K and M dwarfs
M. Zboril 1? , P.B. Byrne 1 , W.R.J.R. Rolleston 1;2
1 Armagh Observatory, Armagh, College Hill, BT61 9DG, N. Ireland
2 Queens University, Belfast, N. Ireland
20 August 1996
It is widely accpted that lithium abundance in latetype stars correlates with other
stellar characteristics, such as age, chromospheric activity and rotation. For example,
the postmain sequence active components of RS CVn binaries have been compared
with inactive field stars of the same spectral type and found to have excess lithium.
In stars with deep convective zones lithium is expected to be destroyed in a relatively
short time. This is most dramatically true in the latest type main sequence stars.
In this paper we have examined the lithium abundances in a sample of lateK
and Mtype dwarfs. High signaltonoise, high spectral resolution spectra have been
obtained of the Li I resonance doublet (–6707.8 š A). Evidence for an appreciable lithium
abundance has been found in stars as late as early to midM. Furthermore, there is
evidence for a correlation between this Li abundance and chromospheric activity in the
case of K dwarfs while M dwarfs do not appear to follow such a relation.
Key words: Stars: latetype -- Stars: lithium abundance -- Stars: chromospheric ac